This morning, there were some justifiably skeptical responses when Marco Rubio’s campaign said they aimed to raise $787,000 in ten days. (Yes, Scott Brown had some million-dollar days, but that fundraising effort had the advantage of urgency; the election was only a few days away.)

But Sen. Jim DeMint’s Senate Conservatives Fund PAC is helping out, and Rubio’s pledges are up to $108,700, which is a pretty good start.

As I mentioned on Twitter, I think if Rubio hits his fundraising mark, his main rival in the GOP primary, Gov. Charlie Crist, will find some other avenue for his ambitions. A new poll has him down 12 in the primary, he does no better than Rubio in general-election matchups, and he’s left looking for a new justification for his candidacy, having established himself as a moderate man in a distinctly immoderate year. Choosing to run for reelection as governor would scramble the already-underway race for that office, but Sen. Bill Nelson is up for reelection in 2012, and conservatives might be a little wary of taking on a two-term Democratic senator.

Crist could salvage some goodwill from conservatives if he were to withdraw now. He might look squishy and uninspiring next to Rubio, but in the eyes of Florida Republicans, he looks a lot more appealing than six more years of Nelson.

UPDATE: Rubio’s pitch for his “stimulus bomb”: