Republican presidential candidates revved up discussion Wednesday night of the 2008 and 2009 auto bailouts of General Motors Co. and Chrysler Group LLC during the 20th, and perhaps final, Republican debate in Arizona.

All four Republicans reiterated their stances against the automotive industry bailouts, albeit for different reasons. Meanwhile, Mitt Romney took the most heat from his fellow contenders for being inconsistent with his views on the auto industry and Wall Street bailouts.

The discussion was prompted by a question from a viewer, Larry N., who asked, Why was George W. Bush wrong in his efforts to save the auto industry and why was Barack Obama wrong to continue the effort?

That quickly turned into an exchange dominated by the two Republican front-runners of Romney and Rick Santorum.

CNN debate moderator John King asked the former Pennsylvania senator to respond first. Santorum is locked in a tight head-to-head battle with Mitt Romney in auto-industry-heavy Michigan, which votes in its primary on Tuesday. King asked Santorum to address a worker in the auto industry that believes he or she still has that job because of the auto bailout.

I would say to them that I in principle oppose government coming in and bailing out a sector of the economy or an industry with government dollars and with government manipulation of that market, Santorum said. Which is exactly what happened twice -- in 2008 and 2009.

Santorum went on to criticize Romney for not being consistent with his positions on the auto bailout vs. the Wall Street bailouts, in contrast with his own positions.

I have one, Santorum said. Not just when they're convenient for me.

Romney was quick to respond, amid scattered cheers and boos from the audience in Arizona after Santorum's remarks.

Nice try, Romney said, but let's now look at the facts.

Romney has drawn heat from both Republicans and Democrats for his stance on the auto industry bailouts. Some Republicans, like Santorum, accuse him of not being consistent in his principles. Some, like Michigan Gov. Rick Snyder, have said the bailouts worked. Some have just criticized him for being overtly vocal on the topic.

Democrats, on the other hand, have taken aim at a New York Times op-ed Romney wrote in 2008, entitled Let Detroit Go Bankrupt. This includes President Barack Obama, who in jump-starting his own re-election campaign has lambasted the proverbial some that were willing to let the auto industry die.

On Wednesday night, Romney reiterated why he believed GM and Chrysler should have gone through a managed bankruptcy process with little or no government involvement, instead of the methods that both Obama and President George W. Bush practiced in 2008 and 2009.

If they go through that managed bankruptcy and shed the excess of costs that has been put on them by the UAW [United Auto Workers] and by their own mismanagement, then if they need help coming out of bankruptcy, the government can provide guarantees and get them back on their feet.

No way would we allow the auto industry in America to totally implode and disappear.

He added that with the Wall Street bailouts, he worried along with Bush that there was a high risk of all banks collapsing.

Romney turned to Santorum, listing off that the Senator had supported the government's airline industry bailout after the Sept. 11, 2001, terrorist attacks. Later, Santorum said the comparison wasn't apples to apples, saying that the government had shut down the industry after the terrorist attacks and had stopped the industry from funding.

When former House Speaker Newt Gingrich was brought into the debate, he said he agreed with Romney's views of a managed bankruptcy option for the auto companies.

The result was what you had was what I thought was an unprecedented violation of 200 years of bankruptcy law by Barack Obama, Gingrich said.

Meanwhile, Texas Congressman Ron Paul had the line of the night in the debate, which went along with his lines on many of the debate subjects.  King, the moderator, asked Paul to respond to Snyder's assertion that the bailout had really worked.

That's sort of like if a criminal goes out and robs a bank and he's successful, Paul said. And therefore, you endorse what he did because he's successful.