Manchester Mayor Frank Guinta hasn't raised big money yet, and now he's got an expensive primary to thank for it.

Republican National Committeeman Sean Mahoney is set to launch his own campaign for the GOP nomination to face Rep. Carol Shea-Porter (D-N.H.), and he could pose a well-funded threat to the frontrunning Guinta.

A source close to Mahoney confirms he is "beginning the process of buttoning up informal commitments that grassroots activists, folks from the donor community and Republican officials have made to him recently."

Mahoney's entry shouldn't be surprising. In the current issue of the magazine he publishes, BusinessNH, included in the Publisher's Note is a full-throated endorsement of the Tea Party movement. Mahoney appears to be setting himself up as the Tea Party candidate in the race.

Mahoney faces a crowded field that includes Guinta and two other businessmen -- Rich Ashooh and Bob Bestani -- but he could separate himself from the pack with the ability to self-fund. No GOP challenger had banked even $175,000 by year's end.

Mahoney's likely entry was first reported by the New Hampshire Union Leader.