While the presidential campaign hasn't officially started,
leads the pack in pre-campaign fundraising by a handful of potential Republican presidential contenders, according to records filed with the Federal Election Commission.
The former governor of
and millionaire founder of Bain Capital raised more than $5.5 million in 2010 through Free and Strong America, his federal political action committee. The PAC closed out the year with nearly $800,000 in cash on hand.
Second place goes to
. SarahPAC raised more than $3.5 million and ended the year with about $1.3 million in cash. Former Minnesota Gov.
raked in $2.1 million but closed out 2010 with just $155,000 on hand.
Former Arkansas Gov.
and former House Speaker
each raised under $1 million through their federal PACs last year.
Those numbers include some but not all of the money that's been raised through state PACs -- a tactic that allows potential contenders to take advantage of more lenient state fundraising rules. Once they become official candidates, they'll be required to route their fundraising through presidential campaign committees, which carry stricter contribution limits.
Romney has created the largest such network with state PAC affiliates in
. With federal and state fundraising combined, Romney raised $6.3 million and had $1.4 million in cash going into 2011.