Over the last few days of the race, Donald J. Trump intends to travel all over the country. He's going to Florida, North Carolina, Nevada, Colorado, Iowa, Michigan, Wisconsin, Pennsylvania, New Hampshire and even Minnesota, he said Saturday.

It’s an impressive travel schedule, but it may reflect the biggest challenge facing him right now: It’s still not clear exactly where and how he would win.

Hillary Clinton has a consistent and clear advantage in states worth at least 270 electoral votes, even if the race has undoubtedly tightened over the last few weeks. But even that understates the challenge facing Mr. Trump’s campaign: It’s not at all obvious where he has his best chance of breaking through, making it harder for him to concentrate his efforts over the last days of the campaign.

This is not to say that Mr. Trump can’t win. The polls could be off across the board.

But even if he wins Arizona, Iowa, Ohio, Utah, North Carolina, Florida and New Hampshire, he's still short of a victory.