The passions of conservative activists could be reshaping the Republican Party and complicating some 2010 re-election campaigns.
Indiana's Mark Souder is among four House Republicans likely to face primary opponents drawing strength from the "tea party" movement and its fervent opposition to anything that might trigger higher taxes or bigger government.
Souder, first elected in the Republican wave of 1994, usually lines up with his party's right wing. But he has angered some conservatives by endorsing earmarks for his district and by backing both the 2008 financial industry bailout (PL 110-343) and the expansion of the program to help recreational vehicle makers.
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