(Washington) John McCain’s choice of Sarah Palin as his running mate has boosted Republican chances of holding key Senate seats and denying Democrats a filibuster-proof majority next year, the GOP’s Senate campaign chief says.

“Their incumbents are in a worse position now than they’ve been all year,” said Matthew Miller, a spokesman for the Democratic Senatorial Campaign Committee.

The National Republican Senatorial Committee still lags far behind its Democratic rival financially and public polls show GOP candidates trailing in competitive contests and the party’s incumbents tied in several others.

Sen. John Ensign, R-Nev., the campaign arm’s chairman, said adding the Alaska governor to the ticket “totally changed things,” giving his party a chance at reducing its losses in the November election to one or two seats. Democrats hold a razor-thin 51-49 Senate majority.

They hope to control 60 seats, a supermajority that would let them bypass parliamentary hurdles without Republicans’ help.