Associated Press
President Barack Obama speaks at the United Auto Workers conference in Washington, Tuesday, Feb. 28, 2012.\r\n

WASHINGTON — In a politically sizzling attack, President Barack Obama on Tuesday accused his Republican presidential challengers of abandoning the American worker and took credit for the auto industry's resurgence while singling out GOP opposition to the taxpayer-backed rescue of General Motors and Chrysler that he helped engineer.

Speaking to a raucous United Auto Workers audience, Obama said that assertions by Republican presidential candidates that union members profited from the taxpayer-paid rescue are a "load of you know what."

Even though Obama did not mention his critics by party or by name, the speech's delivery and content had all the makings of a political stump speech. Even the timing had political overtones, purposefully delivered just as voters in Michigan — a center of auto manufacturing — went to the polls to cast their ballots in the state's Republican nominating contest.

Union president Bob King praised Obama as "the champion of all workers" who "saved our jobs and saved our industry," an introduction that elicited chants of "four more years!" from a crowd estimated at about 1,700 UAW members.

In highlighting the auto industry's comeback, Obama drew a distinct contrast with Republican presidential candidates such as Mitt Romney and Rick Santorum, both of whom have said they would not have used government money to save GM and Chrysler.

Still, the White House took umbrage at suggestions that the speech was political, insisting it was a policy address about the state of the auto industry.

"These are substantive policy issues that affected hundreds of thousands, even millions of Americans," White House spokesman Jay Carney said. "And they're very worth speaking about, as president."