What does the best evidence tell us about who will win the Kansas caucus Saturday?
The only recent poll in Kansas shows Hillary Clinton and Donald Trump in the lead by small margins. But about 40 percent of voters said they were undecided, and it was a relatively small sample size with a large margin of error.
One of the best clues to how Kansas might vote is Oklahoma. Not only are Oklahoma and Kansas neighbors, their populations have a similar racial and socioeconomic makeup, a similar urban/rural split and a relatively similar electoral size.
Several polls in Oklahoma predicted Clinton and Trump to win, but they turned out to be mostly wrong. No poll predicted Ted Cruz’s victory, and only one poll showed Bernie Sanders in the lead.
Racial, economic makeup
Racial makeup has been one of the best predictors of the Democratic primaries.
Sanders has done better in places where there are a lot of white voters, such as Minnesota, Vermont and Oklahoma. The only state that ran counter to that Tuesday was Massachusetts. Because Kansas has a large white population, Sanders has a good shot at winning here Saturday as well.
Some exit-poll analysts say Sanders won Oklahoma but lost Massachusetts because Oklahoma has more low-income white voters. The higher-income white voters in Massachusetts tended to vote for Clinton. But in Kansas the electorate will be much closer to Oklahoma’s. Kansas’ economy is most similar to Oklahoma’s, according to fivethirtyeight.com.
Primary vs. Caucus
About two-thirds of Oklahomans voted for a Republican in the past five general elections; three-fifths of Kansans did.
But Kansas and Oklahoma have not voted as consistently in primaries and caucuses as in general elections. In 2008, the more centrist John McCain won in Oklahoma while the more conservative Mike Huckabee crushed the field in Kansas. And while Barack Obama easily beat Hillary Clinton in Kansas, Clinton won by 24 points in Oklahoma.
Part of the reason for these differences is that Oklahoma holds a primary and Kansas holds a caucus. More than 333,000 Oklahoma voters picked McCain, while fewer than 25,000 Kansas voters selected Huckabee. Because caucuses require more time and energy, they tend to draw the most fervent and, oftentimes, ideologically extreme voters, according to Burdett Loomis, a professor of political science at the University of Kansas. In 2008, Obama, who received more support from liberal voters, won most of the caucus states, while Clinton, the more centrist candidate, did relatively better in primaries.
If the same holds true this year, it would be good news for Cruz and Sanders, who have drawn support from the most ardent conservative and liberal voters.
Both Marco Rubio and Trump were fewer than 10 points behind Cruz in Oklahoma, so small shifts in the electorate this week could change the outcome. For example, the 6 percent of Oklahoma voters who chose Ben Carson could move toward Cruz, another evangelical candidate, now that it's looking more and more as if Carson will be out of the race soon.
In addition, 20 percent of Republicans on Super Tuesday were deciding at the last minute, according to one poll cited by CNN. Already Cruz, Rubio and Sanders have planned visits to try to stir up their bases.
Because so few people tend to vote in Kansas’ caucuses, a shift of just a couple of thousand votes could sway the state toward one candidate or another. That means, of course, that a college basketball game that draws Sanders supporters could have a big impact. But it also means that a good ground game for Sanders, or any other candidate, could swing the caucus in the other direction.