When people find out I am a political reporter, they usually have only one question for me: "Donald Trump can't really win this thing, can he?" My answer is always the same these days: Absolutely he can.

The reason is simple: Trump is the national front-runner, yes, but he is also ahead in a two key early states -- New Hampshire and South Carolina -- and a strong second in Iowa, the state that kicks the whole presidential process off on Feb. 1.

Could he totally collapse from that position? Sure. As we know from recent history, voters in Iowa and New Hampshire don't start paying all that close attention to the race until about 30 days or so out from the actual vote -- meaning that polling on what the race looks like tends to be an inexact science.

But the fact that Trump is ahead nationally and that he is running first or second in Iowa and New Hampshire is meaningful, argues Sam Wang over at the Princeton Election Consortium.

Wang's argument is that based on recent electoral history and where Trump stands in polling today, the real estate billionaire actually has a very good chance at being the Republican nominee. Look at where the past nominees in each party were at this time in national, Iowa and New Hampshire polling:

Sure, there's John Kerry, who was fourth nationally and third in Iowa at this point but went on to win both of the first two states and quickly wrap up the nomination. But the overall trend is clear; running first nationally and standing in either first or second place in Iowa and New Hampshire tends to be a very good predictor of your chances at being the nominee.

Here's Wang's chart with Trump's current standing factored in:

"This emphasizes the fact that based on polling data, Donald Trump is in as strong a position to get his party’s nomination as Hillary Clinton in 2016, George W. Bush in 2000, or Al Gore in 2000," writes Wang. (The bolding is his, not mine.) "The one case in which a lead of this size was reversed was the 2008 Democratic nomination, which very was closely fought."

It's important to remember that Wang isn't saying that Trump will be the Republican nominee. What he's saying is that Trump has a pretty damn good chance at being the GOP nominee -- if past is prologue.

The simple fact is that it is difficult to fall from the lofty perch that Trump currently occupies fast enough to not have a real chance at the nomination. Just one month from now, the Iowa and New Hampshire votes will have already happened!

Barring some sort of massive flub or campaign catastrophe -- and it's hard to imagine what would even fit that description when it comes to Trump -- The Donald will be in the mix when the nomination gets decided.

And, if you're wondering where Trump's rivals for the nomination fit in Wang's calculations, the only one who comes close to the reality star is Ted Cruz, who is second nationally, first in Iowa and third in New Hampshire. Marco Rubio, widely seen as the establishment front-runner at this point, is third nationally, third in Iowa and second in New Hampshire. Jeb(!) Bush? Fifth nationally, sixth in Iowa and sixth in New Hampshire.

The race might not be Trump's to lose just yet. But it's starting to get very late for him to collapse.