FORT WORTH, Texas (AP) — Republican Sen. Ted Cruz, of Texas, sought to fend off an underdog challenge Tuesday from Democratic Rep. Colin Allred in one of the year's most expensive races, which is testing shifts in America's biggest red state and could factor into the fight for U.S. Senate control.

The race that could determine who controls the U.S. Senate. An Allred victory would give Texas its first Black senator and boost the Democrats' chances of maintaining their narrow Senate majority. Cruz winning would mean a third term for the incumbent Republican.

Republican incumbent Ted Cruz and Democratic challenger Colin Allred returned to the Dallas area to make their closing arguments in the final days of Texas’ red-hot U.S. Senate race. Cruz fired up supporters Friday at a Plano “party barn” where the walls were covered in old-timey memorabilia.