AMERICA’S capital, filled with politicos and pundits, is a noisy place. But the howls of one group have risen above the rest. The “Blue Dogs”, a group of 52 fiscally conservative Democratic congressmen, have been at the centre of the fight over health care, after threatening to torpedo the climate-change bill in June. Barack Obama invited a group of them round to the White House on July 21st. Henry Waxman, chairman of the House Energy and Commerce Committee, wooed them with a bouquet of compromises. On July 29th Blue Dog leaders managed both to win a deal and humiliate Nancy Pelosi, the House Speaker. Their delay is likely to prevent her from bringing the bill to a full vote before the August recess.

The Blue Dogs’ evolution has proceeded in fits and starts. After the Republicans seized Congress in November 1994, a group of mostly Southern Democrats formed a coalition to distinguish themselves from their own party liberals. They said they were yellow-dog Democrats (a traditional Southern term for a loyalist who would vote for a yellow dog so long as it was a Democrat) “choked blue” by their leaders. Their main goal has been to resist the tax-and-spend policies too often pushed by their party’s barons; their home-page features a federal debt clock that on July 30th stood at $11,226,807,380,955.11. But for much of the past 15 years they have been a marginal force.

Since 2006 the Blue Dogs have enjoyed a new era of influence. They helped swing the House to the left—11 Blue Dogs seized Republican seats in 2006 and a further five in 2008. Since the start of this year, without the threat of a Republican presidential veto, their clout has grown. Contributions to the Blue Dogs’ political action committee look set to break previous records, according to the Centre for Public Integrity, based in Washington, DC. Charlie Stenholm, a former congressman and founding Blue Dog, contends that “this is the first year for the new kennel in which their votes are really going to make a difference.” A victory came on July 22nd, when the House passed a bill requiring any new spending or tax cut to be offset elsewhere. The debate over health care, however, may be the pinnacle of the group’s power so far. Seven Blue Dogs on Mr Waxman’s committee refused to let a bill proceed without more measures to contain costs.

Despite all this, the Blue Dogs’ grip on power is far from secure. The group does not always vote as a block. Its members, hailing from swing districts, are inherently vulnerable. What is more, some say their centrist role is overstated. The Blue Dogs are more conservative than average Democrats, but their voting record is closely aligned with their party nonetheless, according to a study by Burdett Loomis of the University of Kansas. Only 12 voted against a bail-out of the car industry last December. Only ten voted against the stimulus bill. Robert Borosage of the Campaign for America’s Future, one of many critics on the left, thinks the Blue Dogs bend their ideology when it suits their district, be it a rural area or one dependent on coal.

Nevertheless, the Blue Dogs are carving out a distinct role in a partisan era. Congress has become much more polarised since the 1960s, according to an analysis of party votes by James Thurber of American University. “Partisan extremism has meant that the vast majority of Americans feel unrepresented,” argues Jim Cooper, a Blue Dog from Tennessee. Blue Dogs, he says, provide a voice of moderation. For now, at least, the group has the attention of the White House, party leaders and the media. The dogs are having their day.