BUTLER, Pennsylvania — Thousands of supporters of former President Donald Trump descended on Butler, Pennsylvania, for his return to the place where he almost lost his life three months ago.

The demonstration of enthusiasm on Saturday, particularly from first-time rally-goers, may become an important advantage for Trump during the next 31 days, in which voters have to cast their ballots in an election that is predicted to be decided at the margins in battlegrounds such as the Keystone State.