FOR ALL INTENTS and purposes, the only national political story on August 8 was Ned Lamont's defeat of Joe Lieberman in Connecticut's Democratic Senate primary. But all that Nedrenaline obscured another anti-incumbent surprise the very same night. In Michigan's Seventh District, Republican Representative Joe Schwarz was knocked off by a conservative primary challenger. It was an ominous sign of the national mood for sweaty-palmed Washington Republicans. But it was also significant for another reason: The Club for Growth had finally scalped its first incumbent.