Donald Trump's Republicans were projected to pick up another U.S. Senate seat on Thursday and appeared to be retaining their narrow hold on the House of Representatives, putting them on track to control both chambers of Congress next year.

Control of the U.S. House of Representatives still hangs in the balance after Republicans won the Senate early Wednesday. Follow the latest AP race calls, results and updates on who's winning.

Texas' senior U.S. senator, John Cornyn, is hoping to convince his Republican colleagues to name him the next Senate majority leader. Why it matters: Come January, the new Senate majority leader will grease the legislative skids for President-elect Donald Trump's agenda.

Sen. Josh Hawley (R-Mo.), a rising conservative star, announced this week that he will support Sen. John Cornyn (R-Texas) in the Senate Republican leadership race, giving Cornyn his first public endorsement in the Senate GOP conference.