Are the democrats supporting Obama's reelection underestimating Bachmann?

They label her as "crazy" and "moronic" but she so far has beaten many expectations. She's been elected 3 times in a very liberal state (one of the only two who didn't reelect Reagan) and she slams Obama everywhere she goes. In 2010, a tea partiers were polled and most said that Bachmann was the leader of the Tea Party, not Palin. Speaker Boehner trusts her enough to be on the Intelligence Committee. Even Chris Matthews says she's a threat. Yet, liberals just laugh and think Obama will stomp her. Are they making a mistake.