In 2006, MI-07 Republican Rep. Joe Schwarz was primaried out by Club for Growth-supported wingnut Tim Walberg. Walberg now faces a stiff challenge from Mark Schauer, and Schwarz is getting his revenge:
Former U.S. Rep. Joe Schwarz is endorsing Democratic challenger Mark Schauer in his former south-central Michigan congressional district, even though he's a Republican.
Schwarz told The Associated Press on Tuesday that he decided to endorse Schauer over Republican Rep. Tim Walberg because the anti-tax Club for Growth began running ads critical of Schauer.
This isn't the first Republican brought down by the CFG to endorse a Democrat this cycle. In MD-01, Wayne Gilchrest first endorsed Democrat Frank Kratovil as his replacement, then Barack Obama for president. He even went so far as to do an ad for Kratovil:
How long will attempts at ideological purity be worth it for the CFG if their attempts to excise moderates from their party lead to more Democrats elected with prominent bipartisan support?