On Tuesday, Sarah Palin toured the battlefield at Gettysburg, on the latest stop of her "One Nation" bus tour. The trip, which kicked off Sunday in Washington, D.C., has sparked renewed speculation about Palin's presidential intentions. But while reporters play "a cat-and-mouse game" with Palin, trying to figure out where her bus will head next, a number of conservative commentators have responded to Palin's building buzz by rattling off a few reasons the former Alaska governor isn't ready for the White House. Here, three criticisms of the Mama Grizzly:

1. She can't be trusted with nukes
The "threshold question" when picking a president is "Should we give this person nuclear weapons?" said George Will on ABC's This Week. With Palin, that question "answers itself." Palin is a "genius" at manipulating the media, and she can have a big impact on this race, but she's not ready to handle the nuclear football.

2. She can't handle the 3 a.m. crisis call
Being president is about being woken up in the middle of the night and handed a crisis. "Does anybody think Sarah Palin's ready for that? I don't think so," said David Brooks on NBC's Meet the Press. People may like Palin, and agree with her on many of the issues, but "running for president is not American Idol." Ultimately, people won't think she's qualified to be president.

3. "She's not a team player"
Palin proved this weekend that she could still draw crowds and cameras, but she also made it clear that she "is in business for herself," says Jonathan S. Tobin at Commentary. Palin seems "anxious to prove that she has no use for" other Republicans, and at this stage she's right — her megawatt star power is enough. But "her complete lack of organization will eventually come back to haunt her." Politics is a team sport. Palin has "got to play as part of the team," adds Brooks, but she's given no indication she's willing to do that.