With his 2014 re-election campaign underway, McConnell has seemed less hawkish at times. Earlier this year, he joined 12 other Republicans in voting to cut off U.S. aid to Egypt. Israel opposed the move, but tea party Republicans such as Paul and Ted Cruz of Texas pushed it nonetheless.
Such votes haven't appeased Matt Bevin, the tea party-affiliated Kentucky businessman trying to oust McConnell in the Republican Senate primary. Bevin strongly opposes intervention in Syria and accuses McConnell of being a wishy-washy conservative across the board.
"It's a very difficult position for McConnell to be in," said Dan Schnur, a former top Republican adviser who teaches political science at the University of Southern California.
Schnur said Boehner is taking some risks by backing Obama on Syria when many House Republicans have expressed strong reservations.
Boehner "knows that Republicans don't benefit from becoming the isolationist party," Schnur said. Rejecting Obama's Syria resolution, he said, would "take the Republicans back to a pre-Reagan, pre-Nixon, pre-Eisenhower approach to foreign policy."
Some tea partyers and libertarian-leaning Republicans say it's time for that change. Republicans in Chesterfield County, S.C., recently censured Sen. Lindsey Graham, R-S.C., for his strong support of U.S. military action against Syria.
Debbie Dooley, national coordinator for Tea Party Patriots, said she supports an active U.S. presence military abroad, including acts of war, "when a clear American interest is involved." But engaging in Syria "is completely ridiculous," Dooley said, because the civil war factions on both sides "want to destroy us."
Holt, who has advised several Republican campaigns, said mixing local political concerns with national security needs "is always a bad thing." He said McConnell's statement Tuesday leaves ample room for eventually backing an attack on Syria.
McConnell "is being more cautious," Holt said, "and reflecting, 'Why should I support a president who hasn't shown more resolve on the international stage?'"
Holt, generally seen as an establishment Republican, said his party's members "are going to have to overlook their distrust of Obama to do the right thing."
Associated Press writer Bill Barrow in Atlanta contributed to this report.
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