Republican Sen. John Thune of South Dakota was elected new Senate majority leader, replacing Sen. Mitch McConnell of Kentucky, who is stepping aside. The contest to be the face of Senate Republicans is coming to a head this week. One issue contenders might want to avoid during the final stretch is Trump's ambitious tariff plan.

The mild-mannered South Dakotan and top McConnell ally recently made efforts to patch up his relationship with President-elect Donald Trump.

Thune, of South Dakota, beat out Sens. John Cornyn of Texas and Rick Scott of Florida in a secret ballot election to replace Mitch McConnell.