ROSEMONT – Republicans riding high from a string of breaks in their favor are increasingly optimistic about Mitt Romney’s chances to claim the White House in November, even among conservatives who had qualms about making him the party’s nominee.

The bullish take is reflected in interviews with party strategists and activists, including people who supported Romney rivals during the primary season. Mood matters because it can fuel fundraising and volunteer hustle. But some of those GOP players stress that Romney, the former Massachusetts governor, has little room for error if he expects to topple an incumbent president.

The chest-thumping follows a GOP victory in last week’s Wisconsin recall election that saved Gov. Scott Walker’s job. The race galvanized Republicans who saw it as an early 2012 referendum on conservative fiscal principles in an election that was likely to hinge on the shape of the economy.