By opening the door wider to an interest-rate cut in September, the Federal Reserve is on a collision course with the presidential election. For a central bank that judiciously aspires to stay above the fray of partisan politics, confronting a potential policy shift around election time amounts to a lose-lose. Delivering a rate cut ahead of the election could rile up Republicans and former President Donald Trump, but withholding a needed reduction could undermine the economy and upset Democrats. The awkward optics give extra incentive for central bank officials in the coming weeks to set expectations for and explain the...