John McCain tapped first-term Alaska Gov. Sarah Palin to be his running mate on Friday, said Chris Cillizza in The Washington Post’s The Fix blog, and his “surprise pick” is “sure to shake up the race.” Palin, who was the mayor of a small town just two years ago, is “totally unknown and untested on the national stage,” but she has impressive credentials that should reinforce McCain’s image as a reformer.

They say the selection of a vice presidential candidate is a nominee’s first big test, said Steve Benen in Washington Monthly’s Political Animal blog. “If that's the case, John McCain would apparently be a very odd president.” McCain’s central theme is that Obama isn’t experienced enough to be commander-in-chief, but in that department, Palin is “in a league of her own.”

“The heartbeat from the presidency issue is a real one,” said Jonah Goldberg in National Review’s The Corner blog. And the press will make fun of her for sounding like “a rube.” But Palin is “the best of the dark horses because she’s an exciting, exotic (yet heartlandish) female pick.”

And that is a big part of what makes this surprise “an obvious pick” for McCain, said Holly Bailey in Newsweek’s Stumper blog. Palin is wildly popular, supports drilling in Alaska, is pro-life, and fiscally conservative, so the Republican base will love her. And picking the first woman ever on a Republican ticket is just the thing to help “woo upset Hillary Clinton supporters.”