Watch Live: President Trump campaigns in Alabama for Luther Strange

MONTGOMERY, Ala. — President Donald Trump is test driving his political clout in a Republican runoff election in Alabama as he stumps for the establishment-backed incumbent over an upstart beloved by many of his own most ardent supporters. Buoyed by the sense the race is newly competitive, Trump heads to Huntsville, Alabama, on Friday to campaign for Sen. Luther Strange, appointed in February to temporarily fill the seat that opened up when Jeff Sessions became attorney general. Trump, who endorsed Strange last month, tweeted Friday: "Will be in Alabama tonight. Luther Strange has gained mightily since my endorsement, but will be very close. He loves Alabama, and so do I!"