Any Economic Downturn Could Scramble Trump’s 2020 Strategy

The president projects optimism about the economy and his re-election chances, but his advisers are watching markets closely.

President Trump has made the strong economy the central selling point of his presidency, and his advisers believe it is the key to winning a second term.

But this week’s damaging economic developments—resulting in fresh warnings of a possible impending recession—threaten to complicate that message 14 months before the election.

Mr. Trump and his advisers say publicly they aren’t worried. White House officials add that Mr. Trump—even as he continues to heap...