The endorsement allows Lamborn, who has struggled with fundraising, to get some financial assistance as he faces a rematch of the bitter 2006 primary that pitted him against Jeff Crank, a business consultant who previously worked for former GOP Rep. Joel Hefley.
“Doug Lamborn had one of the most pro-growth records last year in Congress. He has proven himself to be an unwavering defender of taxpayers and the kind of representative Colorado Republicans can be proud of,” Club for Growth President Pat Toomey said in a statement.
Lamborn emerged as the Republican standard-bearer in the district after a particularly nasty Republican primary in 2006. In the race’s final weeks, third-party groups backing Lamborn sent out mailers accusing Crank of being a tax hiker and an advocate for the "radical homosexual lobby."
The mailers infuriated much of the state’s GOP establishment, and Hefley refused to endorse Lamborn in the general election.
Since his election, Lamborn drew unwanted publicity after leaving threatening voicemails with a constituent after the constituent wrote to the community newspaper accusing him of accepting money from the gambling industry. And he only banked $145,000 at the end of the year, leaving him vulnerable to a repeat challenge.
A third candidate, retired Maj. Gen. Bentley Rayburn, is also running again in the Republican primary, scheduled for August 12.