For the GOP, the cavalry apparently isn’t coming. Republicans attuned to conservative third-party efforts say that with less than two weeks to go until Election Day, the prospects for any 11th-hour, anti-Obama ad campaign are highly unlikely. Many in the party, including inside the McCain campaign, have held out hope that a deep-pocketed benefactor would emerge to bankroll ads in the campaign’s final days – spots that might, for example, resurrect the most incendiary clips from the Rev. Jeremiah Wright. But thanks largely to lack of passion for McCain within the conservative base, diminished hopes that he can win and...