Most of the national attention, when it has turned to Texas this year, has been focused on U.S. Rep. Beto O’Rourke (D-El Paso) and his challenge of U.S. Sen. Ted Cruz (R). Polls have consistently shown him trailing by just single-digits in a state that hasn’t sent a Democrat to the U.S. Senate in 30 years. O’Rourke shattered fundraising records in the third quarter. Cruz is less popular among virtually every demographic and political group than Gov. Greg Abbott (R). While those are all reasons for optimism, if you’re on Team Blue, the race has shown no signs of tightening further.

A Quinnipiac poll conducted this month showed the same Cruz lead as a month earlier. This could be indicative of O’Rourke’s inability to make up the remaining ground, regardless of his financial advantage. It could also be indicative of basic math.

The national media are largely ignoring the gubernatorial race between Gov. Greg Abbott (R) and former Dallas Co. Sheriff Lupe Valdez (D), probably because most polls since August have shown Abbott leading by 16-20 points. These are the same voters who will decide the U.S. Senate race here, and a 20-point Abbott win would leave very little room for O’Rourke to catch Cruz.

Let’s get hypothetical. Let’s say that Abbott wins by 20 points, 59%-39%. Assuming Neal Dikeman, the Libertarian nominee for U.S. Senate, gets the same 2% that gubernatorial nominee Mark Tippetts is earning in this hypothetical situation, then O’Rourke would win if he exceeds 49% of the vote. In other words, O’Rourke needs to outperform Valdez by at least 10% of all votes cast. Since 2004, the gap between the highest performing and lowest performing statewide Democratic candidate has exceeded 10% just once, and that year has an asterisk.

In 2006, Bill Moody, a Democratic nominee for the Supreme Court, received 44.9% of the vote, which was 15.1% higher than the 29.8% received by the Democratic nominee for governor, former U.S. Rep. Chris Bell (D-Houston). The asterisk goes with that governor’s race.  Two well-performing independent candidates, former Comptroller Carole Keaton Strayhorn (18%) and humorist Kinky Friedman (12%), skewed the voting patterns of full-ballot voters and shrunk the number of straight-party voters. If we excluded that race, then the next lowest performing statewide Democrat would be U.S. Senate nominee Barbara Ann Radnofsky, who received 36.0% of the vote, which was within 9% of Moody.

We then have to go back to 2002 to find a gap of greater than 10% between the highest and lowest performing statewide Democrats. In that year, former Comptroller John Sharp received 46.0% in his race for lieutenant governor, while Marty Akins received 32.9% against then-Comptroller Carole Keaton Rylander, who was seeking re-election. Roughly one out of every nine voters cast their ballots for Sharp and Rylander, which means that approximately 17% of Rylander’s supporters voted for Sharp. That’s more than one out of every six.

In 2002, an estimated 48% of voters cast a straight-party ballot, and the split between Republicans and Democrats was roughly 54%-46%. If we assume that straight-party voters did indeed stick with all their respective party’s nominees, then the gap between Sharp and Akins can be attributed to full-ballot voters. Sharp received 48% of the vote from full-ballot voters, while Akins got just 21%.

It’s worth noting that the spread between the highest and lowest performing statewide candidates decreases as the percentage of straight-ticket voting increases. Between 2006 and 2014, the percentage of voters casting a straight-party ballot increased to 60% from 43% while the spread between the highest and lowest performing Democratic statewide candidates fell to 4.5% from 15.1%.

In 2014, Greg Abbott defeated then-Sen. Wendy Davis (D-Fort Worth) by 20 points, 59%-39%. Had O’Rourke run for U.S. Senate then, he would have needed 68% of the full-ballot vote to overcome the Republican candidate’s straight-party advantage. Davis received 41%, so a theoretical O’Rourke campaign would have needed 27 percentage points more, and they would have to come from Abbott’s voters. He would have needed at least 44% of Abbott’s full-ballot voters to cross over and vote for him that year. That’s four out of every nine people who did not cast a straight-party vote and voted for Abbott.

It is true that straight-party voters will vote for one or more candidates of another party, but it’s impossible to determine how much support any candidate would receive from another party’s straight-party voters. It also cuts both ways. That’s why we focus on the full-ballot vote needed to win a race like this, because it is practically the only source of large numbers of ticket-splitting voters.

The point of all this is to quantify, at least theoretically, just how high a hurdle O’Rourke has to clear if Abbott wins by 20 points, especially if three fifths of voters are locked into straight-party votes. The polls suggest O’Rourke has made up roughly half the gap. He has another half to go.

©2018 Texas Election Source