Rick Perry's ace in the hole: Rudy Giuliani

Former New York City Mayor Rudy Giuliani continues to mull the possibility of a 2012 presidential bid, but his true power in the race may come if he decides against running and instead throws his support to Texas Gov. Rick Perry.

The two men are good friends, and Perry was the only Republican governor in the country to endorse Giuliani’s presidential campaign in 2008. Payback could benefit Perry on a number of fronts – most notably fundraising – and would likely strengthen his status as a top-tier candidate if he decides to run.