The drop is in large part because of the demographic makeup of likely versus registered voters in Texas. The government’s Current Population Survey found that the electorate that cast a ballot in 2016 was 3 percentage points more white than the entire registered voter electorate. That was tied for the largest increase in the entire nation for white percentage going from registered to actual voters.
There had been some hope among Democrats that O’Rourke’s candidacy might drive higher turnout, which could, in turn, help Democrats in the key congressional races. It’s not clear that’s happening yet.
For example Republican Rep. John Culberson is currently ahead by 2 points in a new Siena College poll of Texas’s 7th Congressional District. Culberson isn’t being helped Cruz. Cruz is down 51% to 44% in the district.
O’Rourke, though, doesn’t seem to necessarily be driving higher turnout among Democrats.