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Yes, the Republican presidential primary is colliding with CPAC this week, but a lesser-noticed (and probably less-interesting) contest is playing out as well: the race for vice president.

The two entrants in that competition who have shown up so far at the three-day Conservative Political Action Conference in Washington are Sen. Marco Rubio of Florida and Virginia Gov. Bob McDonnell. Rubio gave an electric speech Thursday morning, reminding some in the audience of why he might make a good running mate ; a charismatic, telegenic conservative from the swing state of Florida.

This morning was McDonnell's turn. The battleground-state governor made his pitch, not being grandiose but instead calmly going through his record and jabbing President Obama.

McDonnell, 57, quoted the Bible and Ronald Reagan, called for the defunding of Planned Parenthood and public television, stood up for states' rights and the Ninth and Tenth Amendments, and told his audience that he cut spending and taxes.

"Are you ready to fight for those principles?" he asked. (The crowd applauded as if saying "yes.")

"Fiscal conservative principles work," McDonnell said. To Obama, he ordered: "Get the job done. Quit making excuses."

Adding to his resume, McDonnell noted that he's chairman of the Republican Governors Association and, in an effort to earn some more applause, he name-dropped some iconic conservative governors: Scott Walker of Wisconsin, Chris Christie of New Jersey, Rick Scott of Florida and John Kasich of Ohio.

While McDonnell might have a leg up on Rubio, 40, because the governor has actually endorsed Mitt Romney, some conservatives at the CPAC show were hesitant.

Sandra M. Chase, from Fairfax in the northern part of McDonnell's state, said that McDonnell is a fiscal conservative but that he's not as "articulate" as Rubio. "I want the best pick to beat Obama," she said.

"The speech itself was weak," said Rod Sullivan, a Romney supporter from Jacksonville, Fla. "He didn't seem to be a passionate conservative."

Bobby Jindal, the governor of Louisiana who is another potential VP pick, is scheduled to speak Saturday morning.