By Chris Cillizza and Paul Kane
Washington Post Staff Writers
Tuesday, April 28, 2009 5:43 PM

Pennsylvania Sen. Arlen Specter will switch parties and run for reelection in November 2010 as a Democrat, he announced today, a decision that could have wide-ranging consequences for the Senate and President Obama's agenda.

Specter told reporters that he received a "bleak" poll Friday from his advisers that showed virtually no chance of him winning in the GOP primary next spring against Pat Toomey, a former Republican House member who recently led the conservative Club for Growth.

He said that the loss of several hundred thousand GOP voters who left the party in 2008 to vote in the Democratic presidential primary left the Pennsylvania Republican Party too conservative to support a moderate such as him. "I have found myself increasingly at odds with the Republican Party," Specter said.

After more than 28 years in the Senate, Specter acknowledged he was "not prepared to have that record" obliterated by the conservative primary electorate. He reached the decision over the weekend in consultation with his family and top aides, many of whom are staying with him despite his party switch.

He said informed Republican and Democratic Senate leaders about dinnertime last night.

The move brings Democrats to 59 seats in the Senate, just one shy of the 60 they need to exert filibuster-proof control over the chamber. In Minnesota, Democrat Al Franken holds a 312-vote lead over former senator Norm Coleman (R), but Coleman has appealed the result to the state Supreme Court. Oral arguments in the case are expected to begin in June.

Nonetheless, Specter remains an independent voice on many issues, opposing a union organizing bill that is key to many labor groups and rejecting Obama's choice to run a key legal advisory section of the Justice Department. "I will not be an automatic 60th vote," he said.

Specter's announcement, coming on the eve of Obama's 100th day in office, sent shockwaves through political circles.

Specter called the White House this morning to inform Obama of his decision but the president was busy getting his daily economic briefing. When he received a note shortly afterward that Specter was switching parties, the president quickly returned the call, recalled a top adviser who was in the room at the time.

Specter said he received the president's full blessing to run in the Democratic primary largely uncontested next April. "He said he would support me, come to Pennsylvania to campaign for me," Specter said.

Vice President Biden, a long-time friend of Specter's who had counseled him about switching parties, issued a statement late this afternoon saying, "I welcome my old friend to the Democratic Party. Senator Arlen Specter is a man of remarkable courage and integrity. I know he will remain a powerful and independent voice for Pennsylvania and the country."

Republicans immediately sought to cast Specter's move as nothing more than the politics of self-preservation. "Let's be honest -- Senator Specter didn't leave the GOP based on principles of any kind," said Republican National Committee Chairman Michael Steele. "He left to further his personal political interests because he knew that he was going to lose a Republican primary due to his left-wing voting record."

Senate Majority Leader Harry Reid (D-Nev.) said Specter told him last night that he was likely to make the shift, then called the Democratic leader this morning to confirm that his decision was final. Reid credited Biden for playing an important behind-the-scenes role in softening Specter's resistance. Reid also said he and Specter "have had a long dialogue about his place in an evolving Republican Party" and praised his willingness to "work in a bipartisan manner, put people over party, and do what is right for Pennsylvanians and all Americans."

Specter will receive his seniority among Democrats as if he had been elected as a Democrat in 1980, when he rode into office on the coattails of Ronald Reagan's conservative revolution. That effectively means Specter will become chairman of a key subcommittee on the Appropriations Committee, probably the one overseeing the departments of Labor and Health and Human Services. Specter also acknowledged that becoming full appropriations committee chairman -- something that could take another six to 10 years -- "is something I'd like to attain."

As the Senate was wrapping up a procedural vote on popular anti-fraud legislation yesterday evening -- a vote forced upon the chamber by a bloc of hard-line Senate conservatives -- Specter stood by the doorway at the north end of the chamber leading to Reid's office suite on the second floor of the Capitol. According to a Democratic observer, Reid and Specter left the chamber together, entering the majority leader's offices for a private huddle in which Specter confirmed the party switch.

After making the announcement today, Specter turned aside all questions from reporters as he cast a vote on the Senate floor, then joined his wife Joan and son Shanin in the Senate dining room for lunch. He then made a five-minute appearance in the weekly Republican luncheon in the Lyndon Baines Johnson Room, off the Senate floor, where his entrance was greeted with a stony silence.

Specter's political standing in Pennsylvania has become increasingly tenuous in recent years. His track record as a moderate combined with the shrinking Republican base in the Keystone State were likely to make a general election difficult, and Toomey, who came within two points of defeating Specter in the 2004 primary, is running again. Polling showed him with a double-digit edge over Specter in a GOP primary.

The move was the latest blow to an already staggering GOP. Senate Republican leaders appeared ashen at a press conference this afternoon. "Obviously, we are not happy that Senator Specter has decided to become a Democrat," said Senate Minority Leader Mitch McConnell (R-Ky.).

Flanked by GOP colleagues who stared straight ahead, McConnell said Specter visited him in his Senate office late yesterday afternoon "and told me quite candidly that he'd been informed by his pollster that it would be impossible for him to be reelected in Pennsylvania as a Republican because he could not win the primary; and he was also informed by his pollster that he could not get elected as an independent, and indicated that he had decided to become a Democrat."

Grasping for some positive spin on an otherwise catastrophic setback, McConnell warned that Specter's defection could cripple Republican efforts "to restrain the excess that is typically associated with big majorities and single-party rule." He said the pressure would shift to Democrats from conservative states to provide the checks and balances that Senate Republicans would now struggle to provide.

McConnell rejected Specter's assertion that the Republican Party had shifted so far to the right that moderate lawmakers were no longer viable candidates in swing states. "This is not a national story. This is a Pennsylvania story," McConnell said. He said Specter "came to our meeting and talked to us, indicated to me yesterday . . . and again this morning, that he didn't have any problem whatsoever with the way he'd been treated by the Republican conference here in the Senate."

Other moderate Republicans acknowledged they, too, have been approached about changing parties. Sen. Olympia Snowe and Susan Collins, the Maine Republicans who along with Specter provided the three pivotal votes for Obama's $787 billion stimulus legislation, both said today they have been approached. Neither would comment about how recent the overtures were, although Collins said she has been asked roughly four times during her 12 years in the Senate to consider becoming a Democrat.

"It's something I would never do," she said.

Snowe called Specter's decision "devastating news" for Republicans, particularly Northeastern Republicans who have almost vanished in the Senate during the past decade. "Many Republicans feel alienated and disaffected from the party," Snowe said. "It just helps nourish a culture of exclusion and alienation."

Snowe recalled then-Sen. James Jeffords of Vermont, who switched from being a Republican to an independent caucusing with Democrats in 2001. That was a more dramatic switch that flipped power from Republicans to Democrats in the chamber. "Frankly, the party never woke up from that event," she said.

Sen. Lindsey Graham (R-S.C.), a prominent conservative who was John McCain's staunchest supporter in his 2008 GOP presidential campaign, warned that the party has become regionalized in its mentality. "We have to find places in the party for people who couldn't win in South Carolina," he told reporters.

In his remarks to reporters, Specter flashed one brief moment of anger when asked about the role the national Republican Party played in his decision, suggesting his rematch against Toomey will be one filled with a personal vendetta.

He complained about inaction by GOP leaders in Washington when social and fiscal conservatives -- largely funded by the group Club for Growth -- challenged moderate Republicans in primaries. He cited four different races in which the Club for Growth had weighed in and helped a conservative challenger. Each of those seats -- in Maryland, Michigan, New Mexico and Rhode Island -- is now held by a Democrat.

"There ought to be a rebellion, there ought to be an uprising," he said.

Senior White House officials said the decision to switch was Specter's, and he was not lobbied heavily by members of Obama's administration.

"Everyone wanted to give him the space to work things out for himself," a top White House aide said. "We did not dispatch anyone with a basket of goodies."

The one exception was the vice president. In the 10 weeks since the president signed the stimulus bill, Biden has met with Specter face-to-face six times and talked on the phone at least eight times, advisers said.

People close to Biden said the vice president has been urging Specter to make the switch for years. But they said the conversations intensified during the past several weeks as Biden watched political developments in Pennsylvania.

"They certainly talked about the fact that both the vice president and the president would be happy to go to bat for Sen. Specter in every way possible," a top adviser to Biden said.

As Biden pressed his case, aides said he "regularly informed" Obama about the conversations, telling the president recently that he was cautiously optimistic about the prospects.

" 'I talked to Arlan,' " Biden would tell the president, one aide recalled. " 'Still working on him. Still working on him.' [Obama] was obviously aware," the aide recalled.

Specter tried to call Biden early this morning to inform him before news leaked. But aides said the two were unable to connect because Biden was in Texas for an event at the National Domestic Violence Hotline Center.

They talked later in the day.

It was not immediately clear what Specter's decision would do to the Democratic field in next year's Senate race in Pennsylvania. Joe Torsella, the former head of the National Constitution Center, was already seeking the Democratic nomination and raised roughly $600,000 for his bid in the first three months of 2009.

Toomey becomes the odds-on favorite to be the Republican nominee. Toomey held the competitive 15th district for three terms before giving up his seat to challenge Specter in the 2004 primary. He is a favorite of conservatives in the state, but it remains unclear how competitive he will be given the clear advantage Democrats now enjoy in Pennsylvania.

Assuming the court sides with Franken in Minnesota, it will mark the first time since the 95th Congress -- 1977 to 1979 -- that Democrats have controlled 60 or more Senate seats.

Texas Sen. John Cornyn, head of the National Republican Senatorial Committee, said in a statement that the GOP would seek to make the 2010 election a referendum on whether voters wanted Democrats to have unchecked control of Congress. "While this presents a short-term disappointment, voters next year will have a clear choice to cast their ballots for a potentially unbridled Democrat super-majority versus the system of checks-and-balances that Americans deserve," Cornyn said. Earlier this month, Cornyn wrote a letter to Pennsylvania Republicans urging them to rally around Specter, calling him the only GOP nominee who could hold the seat.

Staff writers Shailagh Murray and Michael D. Shear contributed to this report.