Five candidates will be onstage in Texas for Thursday’s Republican presidential debate. But only three of them still have a plausible path to the nomination. And while real estate mogul Donald Trump is the clear front-runner, many political observers think Sen. Marco Rubio (R-Fla.) remains the most likely to overtake him.
One reason is that these political professionals and analysts still think of Rubio as something of a kinder, gentler alternative to either Trump or Sen. Ted Cruz (R-Texas). Sometimes they call Rubio “mainstream,” as MSNBC’s Nicole Wallace did the other night. Sometimes they call him “moderate,” as Commentary’s Noah Rothman did last month. As the theory goes, Rubio's ability to win over less conservative voters could allow him to pick up the votes he needs to stop Trump -- and claim the nomination for himself.
By any reasonable definition, Rubio is not just conservative. He is very, very conservative. You can even prove it with numbers, thanks to a widely used statistical method for measuring ideology.
It’s called DW-NOMINATE, which is an acronym for “Dynamic and Weighted Nominal Three-Step Estimation.” Two political scientists, Keith Poole and Howard Rosenthal, developed the first version in the 1980s and have been tinkering with it ever since.
DW-NOMINATE produces a numerical score for members of Congress based on their voting records. Efforts to measure political feelings statistically are always crude and the DW-NOMINATE scores are no exception. But they give a pretty good sense of where on the political spectrum elected officials lie, particularly relative to one another.
HuffPost Infographic by Alissa Scheller
And Rubio’s score is awfully telling. Zero in DW-NOMINATE signifies the rough ideological center of American politics. Lawmakers with more liberal voting records have scores less than zero, while lawmakers with more conservative voting records have scores greater than zero.
As of the most recent Congress, Rubio’s lifetime voting record is 0.579, which places him firmly on the right end of the Republican caucus. Just nine senators have more conservative voting records than he does.
That makes sense, given that Rubio has been among the reliably conservative votes in the Senate on everything from taxes to the treatment of detainees at Guantanamo Bay. And while Cruz is among those nine senators who are even more conservative, the DW-NOMINATE scores, which are based on voting records, don’t take into account the extreme positions that Rubio has taken up in the campaign -- like promising to rescind President Barack Obama’s executive orders on immigration on “day one,” or opposing abortion even in cases of incest or rape. The gap between Cruz and Rubio still exists, but it’s getting smaller.
As for Trump, his lack of government service means he has no record on which to base a DW-NOMINATE score. But while Trump is by all appearances the most racist, sexist and xenophobic candidate in the race, he’s also taken up several positions -- like support of government negotiation of prescription drug prices -- that are sharply at odds with conservative orthodoxy.
In other words, Trump may be more offensive than Rubio, but he’s probably not more conservative.
Rubio himself is trying to make this argument right now, in the hopes it undercuts Trump’s support before it’s too late to stop him. Rubio hasn’t always been the most candid of politicians. But, in this case, he’s right.
In fact, while comparisons across historical eras are difficult, a candidate with Rubio’s record would probably be the most conservative Republican nominee for president in modern history.
It’s one more sign of just how far the Republican Party has lurched to the extreme fringes of American politics, no matter whom their nominee for president turns out to be.