Senator Ted Cruz of Texas and his Democratic opponent, Representative Colin Allred, met in their first and probably only televised debate on Tuesday night.
The race for the U.S. Senate in Texas has grown closer in recent weeks as the candidates draw on tens of millions of dollars in campaign cash to fight an aggressive advertising war. Both campaigns have sought to appeal to a moderate middle, portraying the other candidate as the more extreme choice.
Polls have consistently shown Mr. Cruz leading. But his margin has not been wide — a survey out on Tuesday from the University of Houston gave him a 50 percent to 46 percent advantage — and Republicans have been concerned. Mr. Cruz is polling slightly behind former President Donald J. Trump in Texas.