President Donald Trump’s effort to stack the Federal Reserve with ideological allies has run into a familiar foe: Republican Sen. Mitt Romney, who’s likely to continue to act as a bulwark against the central bank becoming a target for political appointees. Herman Cain’s decision Monday to withdraw his name from consideration as a Fed governor was largely academic. Romney and three other GOP senators already were poised to torpedo the former Kansas City Fed president and pizza CEO’s nomination if it was brought to a vote.