If we had to pick a symbol of the Republican presidential campaign so far, we'd pick a debate podium.



The podiums have gotten quite a workout this year, as the candidates have met for more than a dozen* debates, plus a handful of joint appearances.



As Paul Farhi notes in the Washington Post today, the debates have gotten remarkably high ratings, with a record 7.6 million people watching the ABC-Yahoo debate on Saturday night.



Tonight's debate in Iowa -- 9 p.m. E.S.T. on the Fox News Channel -- is likely to be the final encounter before the Iowa caucuses, so we wanted to review some of the most interesting fact-checks:



The $10,000 bet. Texas Gov. Rick Perry challenged Mitt Romney over Romney’s book and the health plan Romney promoted when he was governor of Massachusetts. Perry charged that the paperback edition of Romney's book deleted a line that Massachusetts' individual mandate "should be the model for the country." Romney said Perry was wrong and offered to bet him $10,000. Perry wouldn’t go for the bet, but we think Romney would have won it. We found that the paperback edition only had minor changes, so we rated Perry’s statement Mostly False.



Flips and flops. What candidates used to support before they changed positions has been a major debate topic, with charges of flip-flopping being leveled against both Romney and former House Speaker Newt Gingrich. Gingrich said, "I never favored cap and trade," at a candidates’ forum, but we found that False. Bachmann, meanwhile, charged Gingrich "first advocated for the individual mandate in health care. And as recently as May of this year, he was still advocating" for it. We rated that Mostly True.



Getting the numbers wrong. There have been some significant screw-ups in the numbers as candidates have tried to make their points. Gingrich said that in New York City, "an entry level janitor gets paid twice as much as an entry level teacher." Our investigation found Gingrich used the wrong numbers; we rated his statement False.



Attacking Obama. Romney has repeatedly claimed that President Barack Obama "went around the world and apologized for America." We examined that claim, though, and found it’s not true. Obama may have used diplomatic language to express the idea that the United States isn’t always perfect, but he never apologized. We rated Romney’s statement Pants on Fire.



Illegal immigration. Romney charged that Perry was soft on illegal immigration while Perry has been governor of Texas. Between 2000 and 2010, the illegal immigrant population of Texas increased by 60 percent, Romney said, while California and Florida had "no increase." We found that Half True; he was right about the numbers, but we found no evidence that Perry’s policies contributed to the immigration.



9-9-9. He’s gone now, but Herman Cain, the former CEO of Godfather’s Pizza, contributed the catch-phrase "9-9-9" to the Republican debates. The numbers stood for Cain’s tax plan: a 9 percent income tax, a 9 percent business tax, and a 9 percent sales tax. Cain claimed the plan plan did not raise taxes "on those that are making the least." But independent tax experts found that was not the case, because it imposed new taxes on people who now pay little or no income tax. We rated his statement False.



Bureaucrats deciding health care. At a debate in New Hampshire, Michele Bachmann said that "15 political appointees" on the Independent Payment Advisory Board -- an entity created by Obama’s health care law -- "will make all the major health care decisions for over 300 million Americans." She was right that the board has 15 members, and that most are appointed through a political process, although they must have expertise in health care. However, the board is intended to recommend cost savings for the Medicare program. It would not "make all the major health care decisions for over 300 million Americans." We rated her statement False.



Dust in the wind. At a debate in Orlando, Fla., a voter asked via You Tube, "If you were forced to eliminate one department from the federal government, which one would you eliminate and why?" Herman Cain turned his hypothetical ax on a favorite target of big government foes: the Environmental Protection Agency. "Now, I know that makes some people nervous, but the EPA has gone wild," he said. "The fact that they have a regulation that goes into effect Jan. 1, 2012, to regulate dust says that they've gone too far." It turns out that dust is regulated, but not at all in the way Cain described. We rated his statement False.



* The number of debates depends how you count them and whether some of the lower-profile joint appearances are included. NBC's First Read says tonight will be the 13th; the Washington Post says it will be the 16th.