BIRCH RUN, Mich. — Donald J. Trump’s plan to combat the Islamic State? “We go in, we knock the hell out of ’em, we take the oil,” he told Fox News on Tuesday.

How would he handle China, should it keep devaluing its currency? “Well, you have to take strong action,” he said at a news conference here later in the day, right before he took the stage in a hall crammed with about 3,000 people.

And what was his plan to improve race relations, someone asked him a moment later? “You need spirit, esprit de corps, cheerleading, and you need jobs.”

For a man of so many words, Mr. Trump still has relatively little to say about the kinds of policies he would pursue as president.