Senator Ted Cruz (R-TX) debated his Democratic opponent Beto O'Rourke Tuesday night and ended up stumbling over what should have been a very easy question to answer.

One of the debate moderators asked Cruz to tell voters "something you've done in the last year that has nothing to do with politics" so that Texans can form a better "insight to who you are as a person."

Cruz's response, apart from looking like he was just asked to find the solution to quantum gravity, was six seconds of dead silence and a heavy sigh.

The incumbent Republican then said the hardest part about being a Senator "is being a dad," followed by remarks about how tough it is managing a family while working in Washington.

Watch the clip below:

Needless to say, this didn't help Cruz's likeability factor on Twitter. People were pretty amazed that Cruz, himself a sitting Senator and former federal prosecutor, wasn't able to answer a question about his personal life.

Cruz has answered other questions with silence in the past - tough questions at that.

In June, Weekly Standard reporter Haley Byrd asked Cruz if he thinks the president (in this case Donald Trump), has the constitutional authority to pardon himself.

Cruz's response was 18 seconds of silence, followed by saying in a near non-answer that he hadn't studied that part of the Constitution.

The Texas Senate race is one of the most closely-watched and hotly contested this election cycle. Both candidates have raised tens of millions of dollars. The winner of the Texas seat will help determine which party ends up controlling the upper chamber in November.