Republican presidential campaigns are supposed to be simple. Republicans nominate the next guy in line. More precisely, Republicans nominate the guy who ran second the last time around. (And so far, it's always been a guy.)
Ronald Reagan in 1980, George Bush in 1988, Bob Dole in 1996, John McCain in 2008, Mitt Romney in 2012 -- each of them had been the runner-up the last time the GOP nomination was open.
The only exception was George W. Bush in 2000, and that was at least partly because there really was no credible runner-up in 1996. Polemicist Pat Buchanan and publisher Steve Forbes finished with more votes than any other candidates.
And thus, as Michael Kinsley wrote, "it was decided that the Republican candidate for president [in 2000] should be the less impressive of the two political sons of the man who had most recently lost them the White House."
And now the Republicans face another year like 2000. No one from the 2012 primaries seems like a credible candidate this year, so the race is wide open. Some thought the rule would be, "If there is no runner-up, nominate the next Bush in line." But widespread if belated dissatisfaction with the previous Bush presidency has put that plan in jeopardy.
Today Republican voters face a choice among several kinds of candidates.
Leading the polls are two men who have never before sought or held public office, Donald Trump and Ben Carson. Both have a certain appeal but are given to odd, extreme, and offensive comments. Republicans haven't nominated a non-politician since Dwight Eisenhower, and he had been Supreme Allied Commander during World War II. It's highly unlikely that Carson, Trump, or Carly Fiorina will make it to the finish line -- which means that more than half of Republican voters are not yet committed to any likely nominee.
The second category includes the safe establishment candidates, the fading Jeb Bush and Ohio's John Kasich. Both have been twice elected governor of a major state. Kasich also chaired the House Budget Committee. Bobby Jindal could have been this group, except that the Rhodes Scholar who ran Louisiana's health department at 25 decided to play down his 19-year career in public sector management and campaign as a yahoo.
Some observers put Marco Rubio in the establishment category, too. He's handsome, a good speaker, right at the center of the Republican party ideologically. And safe, like Bush and Kasich. The difference is that Bush and Kasich have records of accomplishment. I have yet to find a Rubio supporter who can cite a single accomplishment as senator or as speaker of the Florida House. That may be a problem as voters come to focus on the more plausible candidates and their records, though first-term senators with thin records have been elected before.
The final category would be the inside outsiders, or the anti-establishment politicians -- people with some political experience who still offer a real challenge to the establishment candidates. This fourth group includes senators Ted Cruz and Rand Paul. Like Jindal, Cruz is a product of elite universities campaigning as a tub-thumping preacher. He thinks he can combine evangelical and tea party voters, take libertarian voters from Paul, and then go head-to-head with the last standing establishment candidate.
Paul thinks he can bring out a larger libertarian vote than most observers count on. After all, his more staunchly libertarian father, as a 76-year-old House member, got more than 20 percent of the vote in both Iowa and New Hampshire. He's making a strong push for college students and independents with his stands on marijuana and criminal justice reform.
Despite the conventional wisdom about Republican hawkishness, Paul thinks there's an opening for a candidate who's skeptical of wars in the Middle East and with Russia. He knows that 63 percent of Republicans in a Pew poll -- and 79 percent of independents--said that the Iraq war wasn't worth the costs. Paul and Trump are the only Republican candidates who opposed the Iraq war. In the second debate, Paul said, "If you want boots on the ground, and you want them to be our sons and daughters, you've got 14 other choices. There will always be a Bush or Clinton for you if you want to go back to war in Iraq."
Three months before the first voting in Iowa, there's nothing simple about this Republican race.
David Boaz is Executive Vice President of the Cato Institute and author of The Libertarian Mind(Simon & Schuster, 2015).