The Same Twenty Nine Percent?

According to the latest Rasmussen poll, 29% of Democrats say Hillary should make an independent bid for president if [cough, when, cough] she loses the nomination. "I'm John McCain, and I approve this message."

I wonder how much overlap there is between that 29% and the 29% who approve of Bush's presidency. I mean, is it not possible that 29% of polled Americans just like to make stuff up to jerk pollsters around?