Simply because Texas polling tends to be off by as much as 8% points on average ….
The August polling averages were off by between 5 points and 14 points in any given year. On average since 1990, they were off by about 8 points.
Of course, that error could cut either way — it doesn’t necessarily favor Cruz. The senator leads by 3 points, on average, in polls taken this month. If this year’s polls are off by that average amount — about 8 points — then we really shouldn’t be surprised by anything from Cruz winning by 11 points to O’Rourke winning by 5. And even that understates how wide the range of possible outcomes still is — that’s just what could happen if the polls are off by the average amount. Who’s to say polls won’t be off by 14 points like they were in 1990 and 1994?
None of this is to say O’Rourke has no chance. Expert ratings, such as those provided by the Cook Political Report, Inside Elections and Sabato’s Crystal Ball, have a track record of accuracy in forecasting elections, and all three have pinned the race as either “lean Republican” or “likely Republican,” meaning Cruz is favored but they believe O’Rourke has a shot to at least make the race competitive. Moreover, O’Rourke, a three-term congressman, has pulled far ahead of Cruz in the fundraising race. According to the Texas Tribune’s analysis of Federal Election Commission data, Cruz raised $15.6 million from the start of 2017 through July; O’Rourke pulled in a whopping $23.6 million. That sum makes O’Rourke’s campaign the third-biggest fundraiser among all Senate candidates this election cycle, according to Open Secrets, a nonpartisan research group that traces money in politics….
Still, not a single poll so far has shown O’Rourke ahead of Cruz. So don’t make any serious bets just yet — it’s still too early to get carried away with speculating about big changes in Texas based on August polling alone….