Rep. Mike Simpson (R-Idaho) raised more than $1.25 million in 2013 as he gears up for a GOP primary challenge.

The record-breaking sum for the congressman includes more than $430,000 raised in the fourth quarter alone. He now has just under half of that sum, or $760,000, cash on hand for his reelection fight.

Simpson has continued fundraising at a fast clip throughout the year, breaking a personal fundraising record in the third quarter as well.

He’s facing a Tea Party challenge from Idaho Falls lawyer Bryan Smith, who raised $275,000 last quarter and had over $300,000 cash in the bank for his campaign. He hasn’t yet announced his fourth-quarter totals.

The 2nd District primary is slated to be one of the nation’s hottest, as Simpson, an ally of House Speaker John Boehner (R-Ohio), draws on establishment support to defend him against Smith’s challenge.

The Chamber of Commerce has indicated it plans to go to bat for Simpson, and has already run ads for him. Boehner has hosted a fundraiser for him.

Smith doesn’t want for deep-pocketed supporters, however — he’s nabbed the endorsement of the Club for Growth, a chief Boehner antagonist and a group known for spending millions on competitive races.

--This piece was corrected at 4:43 p.m. to reflect the fact that Simpson represents Idaho.