One of the most important things to understand about a presidential race -- and this goes for both parties -- is that there are a limited number of lanes for the potential candidates to run in.

There are so many lanes to fill for those who want to run for president in 2016.

The jockeying to fill those lanes is what the candidates -- and their political operations --  devote their time to in the several years before anyone outside of people (read: weirdos) like the Fix are paying attention. (We've often compared the presidential race to an iceberg; the part you see above the water is only a tiny portion of the whole thing.)

And, although the Iowa caucuses are roughly 1,032 days away -- who's counting! --  that positioning has already begun.  Below is our first cut at the major lanes and who on the Republican side is filling them at the moment.  Did we miss any lanes?  Tell us in the comments section.

* The establishment lane: Jeb Bush

Former Florida Gov. Jeb Bush. AP photo.

We'd assumed up until this week that Florida Sen. Marco Rubio would fill this lane in 2016. But, Jeb's re-emergence -- and seeming desire to carve space (and time) out for himself heading into 2016 -- means that the former Florida governor will be the default pick of the establishment unless and until he decides not to run. If Bush doesn't go, then Rubio is the default occupier of the establishment lane.

* The reformer lane: Bobby Jindal

Louisiana Gov. Bobby Jindal. Getty Images

The Louisiana governor pushed his way into this lane with a speech he gave earlier this year at the Republican National Committee winter meeting in Charlotte that was heavy on how the party needed to change the way it was doing business. Jindal has also worked aggressively to build a record as a reformer in the Bayou State although his efforts took a bit of a blow Monday when his education reform legislation was struck down by a judge in Baton Rouge.

* The outside DC lane: Chris Christie

New Jersey Gov. Chris Christie. AP photo.

No one likes Washington at the moment so positioning yourself as the guy (or gal) who doesn't get what's going on "down there" -- this applies even if you live south of the nation's capital -- is smart politics. And, the New Jersey governor has repeatedly planted his flag in that space. The latest example was his Monday press conference in which Christie delivered this gem: “I don’t have the first damn idea of what they’re doing down there." And then there was his extended riff on his  problems with Republican House Speaker John Boehner.

* The wonk lane: Paul Ryan

Wisconsin Rep. Paul Ryan. Photo by Chip Somodevilla.

The 2012 vice presidential nominee has kept a relatively low profile since his ticket lost last November but he is still the de facto occupant of the "smart guy with ideas" lane that we have shortened to simply call the "wonk lane".  (We could also name this the "Newt Gingrich honorary lane.")  Ryan's budget -- he plans to introduce the latest version next week -- has become a rallying point for many conservatives who believe that the party needs to outline its own fully-realized vision for governance.

* The conservative lane: Rand Paul

Kentucky Sen. Rand Paul. AP photo.

Barring some strange series of events, the Kentucky Senator -- and heir to the political legacy of his father Texas Rep. Ron Paul -- will hold down this lane throughout the run-up to 2016 and all the way into the race itself.  Paul's libertarian-influenced conservatism may not sit perfectly with some defense hawks but it's hard to see anyone unseating him as the truest and/or most committed conservative in the field.