Supporters at a campaign rally for Beto O'Rourke. Photo: Loren Elliott/Getty Images
The big picture: "Despite his staggering cash haul and quick rise to national prominence, O'Rourke still appears to be an underdog. No recent independent poll has shown him closer than 5 percentage points behind Cruz," CNBC notes. Watch for early voting, which started this week in Texas, and whether Trump's visit to the state on Monday energizes Republican voters.