The anti-tax Club for Growth has labeled the "fiscal cliff" a key vote and urged House members to vote against it.

"This bill raises taxes immediately with the promise of cutting spending later. Tax rates will go up on marginal income, capital gains, dividends, and even certain estates when a person passes away," wrote Andrew Roth, the Club's vice president for government  affairs. "But it also delays the sequester for at least two months, breaking the promise made by Congress in 2011 to cut government spending. And, among other things, it includes an unpaid-for extension of unemployment benefits." 

The group is not shy about getting involved in Republican primaries -- often succeeding in ousting lawmakers or defeating establishment candidates deemed too moderate.