All Boehner needs is enough Democrats to either abstain or vote "present". They don't even have to vote for him.
The Speaker only needs a majority of the Representatives that actually vote for an individual.
So, you have to ask: what do the Democrats fear more? Boehner as Speaker, or a conservative Republican as Speaker? Once you answer that question, how do you think they will vote?
Doubtless many RATs WILL vote for boner. Having him as Speaker is almost as good as having Pelosi.
How did they ever dump Newt, then his replacement?(Name escapes me at the moment)
Character matters.