How Donald Trump could ride to Mike Johnson's rescue

There’s been plenty of speculation about how Democrats might save Speaker Mike Johnson’s gavel as Rep. Marjorie Taylor Greene (R-Ga.) threatens to oust him.

The better bet right now is that if anyone comes to Johnson’s rescue, it will be the most powerful Republican around.

Former president Donald Trump is set to appear with Johnson at an “election integrity” event at his Mar-a-Lago resort Friday — a joint event that hints at a…