LAS VEGAS (CNN) -- Seven Republican presidential candidates engaged in a sometimes contentious debate Tuesday in Las Vegas, Nevada, as bad blood boiled between front-runners and the surging Herman Cain found his opponents taking aim at his tax plan. Here are five things we learned from the debate: Why 9-9-9 was No. 1: A rise in the polls brings more scrutiny, so we knew that Cain's "9-9-9" tax plan would come under attack from his rivals. And we didn't have to wait long for the full frontal assault. In response to the first question of the debate, from an audience member asking the candidates their "position on replacing the federal income tax with a federal sales tax," the other candidates were quick to pile on and rip apart Cain's much-touted proposal to reform the country's tax code, a plan which has helped the former Godfather's Pizza CEO surge in the polls. The six other candidates sharing the stage with Cain fired away, terming the plan as risky and simplistic.
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GOP contenders attack Herman Cain's "9-9-9" tax plan
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Former Mass. Gov. Mitt Romney took some verbal jabs from opponents, but threw some as well
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Texas Gov. Rick Perry did better in this debate than previous ones
"The reason that our plan is being attacked so much is because lobbyists, accountants, politicians -- they don't want to throw out the current tax code and put in something that's simple and fair," responded @placeholder.
After the debate, @placeholder said he was happy with his defense of his plan, but promised a more comprehensive proposal would follow, and he added that the attacks on him are proof that he's now a front-runner in the race for the nomination.
@placeholder admitted that a landscaping company he hired did employ illegal immigrants, but he said he fired the company when he found out.