The head of New York State's Conservative Party said yesterday that it may withhold its endorsement from Gov. George E. Pataki if the governor seeks re-election in 2006, creating a new problem for Mr. Pataki even as he works to calm a feuding Republican Party. A Conservative Party endorsement could prove pivotal if the governor were to find himself in a race against the state attorney general, Eliot Spitzer, a Democrat who has said he plans to run in two years and who has broad support throughout his party. In each of his last two elections, Mr. Pataki could have...