Why did Beto O’Rourke run for president instead of Senate in 2020?

A Quinnipiac poll released Wednesday found that 60% of Texas Democrats or people who lean Democratic would rather former Rep. Beto O’Rourke drop out of the presidential race and challenge GOP Sen. John Cornyn in 2020. Only hours after the poll was released, CBSN’s Elaine Quijano exclusively asks O’Rourke about what his message would be to Democrats in his home state. Source