Ted Cruz is a Southern US Senator. He is conservative, and pro-life, and stands for Tea Party ideals.
So his campaign early on decided that Super Tuesday — today, March 1st — would be a watershed day for them. Of the states up for grabs, a number of them are in the South and would resonate with Ted Cruz's ideals.
There is just one major problem — Donald Trump. Last summer, it was thought the competition might be Jeb Bush or another leader. Today, Donald Trump with his strong anti-immigrant rhetoric has taken some of Ted's thunder.
So, to stay a strong candidate, Ted Cruz must win Texas, his home state, and place well enough in the other Southern states to pick up a large share of delegates. He also has Marco Rubio contenting with him for the #2 to Donald Trump slot. So if Ted does really well tonight, he could be the strong #2 and have a fighting chance. If he doesn't? His road forward gets much more challenging.