Mayor Michael Bloomberg has long hungered to be at the center of the national debate, to be regarded as one of New York's greatest mayors, even to be seen as a possible president. If he becomes a candidate in 2012, and that is still a decided long shot, his speech Wednesday may be seen as the first volley in the battle.

In the guise of offering a blueprint to fix the broken economy, Bloomberg offered a withering critique of the broken politics practiced in Washington and Albany. The politician who started his career as a Democrat, became a Republican to run for mayor and then announced that he was an independent, took aim at left and right with equal abandon.

He attacked the "ideologues on the left" for clinging to the belief that taxing and spending can restore prosperity and for holding a government-knows-best approach to creating jobs. He attacked "ideologues on the right" for entrusting all faith in the free market and writing off any significant role for government in shaping the environment in which the economy can flourish.

"For New York City to continue our growth, we need our federal and state governments to chart a middle way - between a government that would wash its hands of the problem and one that seeks to supplant the private sector; between a government that would stand on the sidelines and one that would take over the game," he said in Brooklyn on Wednesday morning, according to a text of his prepared remarks.

Bloomberg identified the symptoms of dysfunctional politics: partisan gridlock, political pandering, legislative influence-peddling, finger-pointing, blame games and endless attacks. Democrats, he said, lost the 2010 elections for the same reasons Republicans lost in 2006 and 2008. They "spent more time and energy conducting partisan warfare than forging centrist solutions to our toughest economic problems."

The political parties, he argued, fuel the discontent instead of finding ways to improve people's lives. "They incite anger instead of addressing it, for their own partisan interests," he said. They follow the public mood rather than shape it.

"When did cooperation in government become treason?" he asked. "The new 'politics as usual' is making a mockery of our democracy and a mess of our country. We've got to stop it, because we're paying a heavy price. In fact, right now, we are falling behind the world in education, technology, economic opportunity - even life expectancy."

He praised the agreement between President Obama and congressional Republicans to extend the George W. Bush-era tax cuts for two years and extend unemployment benefits for 13 months. But he chastised politicians in Washington for not moving immediately to take up the recommendations of the national debt and deficit commission. "We need more than a commission and more than lip service," he said. "We need results. And not next year or the year after, but now."

He offered six principles for restoring the nation's economic prowess: Instill confidence and create certainty from Washington, promote trade agreements rather than protecting threatened industries, reform regulations, cut business taxes, invest more in job training, and reform immigration by allowing brainy workers and serious investors to come here and do their work.

Many of those sound like standard pro-business measures, with a strong dose of leadership from Washington, shorn of ideology and measured largely by results. No doubt many in both parties would agree, at least in broad terms, with many of those principles. Forging a political consensus behind such a program is another matter.

What Bloomberg is trying to do - has been trying for some time - is to create a consensus in the middle of the political spectrum and convert that into a movement strong enough to reshape the nation's politics. And perhaps allow him to run for president someday.

That depends in part on forces beyond his control, on his hope that the political terrain will be more open to a centrist candidacy than it was four years ago. Then he had his eye on running, only to see Republicans and Democrats nominate the two people he knew would close off his candidacy - Obama preaching post-partisan politics and Sen. John McCain (R-Ariz.), whose career had been a demonstration project for working across party lines.

What could make it possible in 2012? One would be a Republican nominee who comes out of the most conservative wing of the party, an ideologue who might turn off the independents who supported the GOP last month. A Sarah Palin. Another would be a weakened Obama, rather than a revived Obama, a president seen by the country as still floundering against an economy stubbornly refusing to respond.

When they looked at this before, Bloomberg's team applied a series of statistical tests that would be used to decide whether the climate was receptive to an independent candidate. Disapproval of the major party candidates had to be high - 35 to 40 percent. Pessimism about the direction of the country also had to be higher, as it has been lately.

But that wouldn't be enough. Polls would have to show a significant percentage of Americans, say 60 percent or better, open to the idea of voting for an independent or third-party candidate. And finally, the initial percentage for that candidate (read: Michael Bloomberg) would have to be sufficiently high - 20 percent probably the absolute minimum - to suggest eventual electoral college viability, given a well-funded and well-run campaign. For it's doubtful Bloomberg would run just to make a point.

That's well off into the future. For now, Bloomberg will keep trying to stoke interest and remain visible. He is setting himself up as the pragmatic critic of business-as-usual in Washington while trying to make America see New York as a story of economic success, not a land apart from the values the rest of the country shares.

His ambitions are large and his pockets deep. But the country remains rooted in two-party politics, dysfunctional as they may be. Whether the mayor can change that equation is questionable. But he will continue to step forward until it's clear he can't - and maybe longer.