Alexander: The Trump Freight Train

Donald Trump won the Nevada caucus Tuesday with almost 46% of the vote, and he is now three for four. Marco Rubio claimed 24% to Ted Cruz's 21%.

For his part, Trump told his supporters, "Now we're winning, winning, winning the country, and soon the country is going to start winning, winning, winning!"

Of the Nevada demographics, he said, "We won the evangelicals. We won with young. We won with old. We won with highly educated. We won with poorly educated. I love the poorly educated. We're the smartest people. We're the most loyal people, and you know what I'm happy about? Because I've been saying it for a long time — 46% were the Hispanics — 46%. Number one with Hispanics. I'm really happy about that." And according to the entrance polling and the exit polling, he is correct.

Though Nevada, like Iowa, is a caucus state, and only 70,000 people turned out, the breadth of Trump's support among those voters was impressive. The commonly held theory that Trump has a "low ceiling" of support, capped at just 30%, is questionable. As Byron York writes, "If he has a ceiling ... it is higher than earlier thought."

The GOP delegate count is now Trump 81, Cruz 17, Rubio 17, Kasich 6 and Carson 4. That is a long way from the 1,237 delegates needed to secure the Republican nomination, but the Trump train is full of steam.

Trump's campaign is a case study of how a wealthy, masterful self-promoter can keep himself front-and-center in the mainstream media, and how that keeps him on top in the polls in a field with multiple opponents. Though Trump could buy his way to a Republican primary victory, he won't have to.

There are three factors propelling Trump's lead.

But before defining those factors, by way of disclosure up front, let me say that I will "vote early and often" for Donald Trump if he is the Republican nominee.

Here is what I know about Trump.