Rubio, a conservative and Tea Party darling, is competing with Florida Gov. Charlie Crist (I) and Rep. Kendrick Meek (D) in a three-way race for the Senate seat. Crist left the Republican party after it became clear he could not defeat Rubio in a primary.

Crist has yet to release his numbers for the quarter. Meek reported raising more than $1 million.  It's not clear how much cash on hand Rubio has.

Rubio’s big second quarter number adds to the pressure on Crist, who despite having a stockpile of cash earlier in the year faces questions about his fundraising potential now that he’s an independent. 

In a statement touting Rubio’s second quarter numbers, the campaign noted that the haul breaks a state record for fundraising during a single quarter — Crist raised $4.3 million in his first quarter as a Senate candidate. In the first quarter of 2010, Crist raised $1.1 million.