Trying to understand the dynamics of the 2016 Republican presidential race is like trying to watch a three-ring circus: There's too much going on to absorb all at once.

The circus analogy may be overused, but thinking of the party in terms of three rings — or to be more precise, wings — can be very useful.

Ronald Reagan was the first candidate to unite the three wings of the modern Republican Party: Christian conservatives, national security hawks, and the Wall Street establishment. His coalition dominated national politics in the 1980s and every GOP nominee since has tried to copy that same electoral formula.

George H.W. Bush always had the establishment and foreign policy credentials but was never fully trusted by evangelical Christians. Being Reagan's vice president helped him win the 1988 election, but he lost his re-election bid in 1992.

His born-again son, George W. Bush, did a better job with the religious right and used his family ties to bolster his reputation with the other two wings. But bungling wars in Iraq and Afghanistan and blowing up the national debt later hurt him. In fact, many think the second Bush broke the Reagan coalition beyond repair. No one has been able to put it back together since.

In 2008, John McCain had the national security credentials, but his maverick reputation hurt him with the GOP establishment and evangelicals never trusted him. In 2012, Mitt Romney had the backing of Wall Street but his Mormonism created a rigid barrier with the religious right and he had no foreign policy experience. Neither man was ever able to pull his party together in a convincing way.

The Republican candidate who performs best with each of these three wings — and unites them — has the best chance of prevailing in the 2016 general election. Looking at the GOP presidential race through this lens brings a clearer view of who might be the best candidate to nominate.

Most of the Republicans running are just one-wing candidates and a few can claim support from two.

In fact, there may be only three candidates with the ability to unite the three wings and rebuild the Reagan coalition. Gov. Scott Walker of Wisconsin and Sen. Marco Rubio of Florida top the list, but both have their weaknesses. Walker has no national security experience and performed poorly on a recent overseas trip. Rubio is young and still unknown to much of the GOP establishment.

Jeb Bush is the third top-tier candidate, but his family's connections are both a strength and a curse. He may have the support of some foreign policy big wigs, but he's also saddled with his brother's foreign policy disasters.

The Republican candidate that can unite these three wings has the best chance to prevail against the Democratic candidate in the general election. It's still too early to say who might be able to do it — but we can at least conclude that only three candidates out of the GOP primary circus have a real shot.