Live updates: Trump taunts Canada over Lake Ontario's name; SC voters set to pick Graham or Norman

Tuesday's South Carolina Republican Senate runoff election between Sen.

Darline Graham and Rep.

Ralph Norman will test President Trump's endorsement power.

MAGA Inc., a super PAC that backs Trump, has invested in Graham's election, and Trump on Monday night touted an Oval Office meeting with the senator.

Norman trailed Graham in the state primary two...