It’s astonishing when you think about it: a reality TV star who was only a joke a year ago became the Republican nominee this week. He accomplishes this without the typical big donor networks, without the typical "establishment" political support, without the early backing of the Republican National Committee and by warring against "big media."

Before Trump, I thought that media wars never work. "Never pick fights with people who buy ink by the barrel" is the old cliché, but of course, in an Internet and social media-driven world, ink is so yesterday.

Trump didn’t just run against the media; he ran against the beltway media. He ran against almost all of our country’s concentrated elites, the people with the power to define and demolish. And he did this by arguably being an elite himself, a billionaire from Manhattan who flies around in jets bearing his name but still appeals to blue-collar folks with beer cans. He accomplished all of this even though he uttered a series of statements that would have done in any other candidate.

We all know this. We’ve followed the saga for months now. However, it’s worth taking a step back and assessing: How did Trump pull this off? Because it really is remarkable. Here are five reasons that Trump managed to become the nominee:

1. Social media

I am not sure we would have "Donald Trump, Republican nominee for president" without Twitter. And I’m serious about that. If you follow Trump on Twitter, you know he’s revolutionized its use as a national politician. His tweets are personalized and casual, and they actually sound like they were written by him!! (the two exclamation points make the sentence sound more Trump-like).

However, I think the real genius of Trump when it comes to social media is how he’s used it to drive the news cycle. I noticed that, before every major primary, Trump would say something particularly crazy. I don’t think this was unintentional. I think he was trying to dominate the news cycle. He uses Twitter especially to own the 24-hour news cycle. He wants to dominate the conversation; whether they are trashing him or praising him, he’s still the person they are talking about. This is worth millions upon millions of dollars in free advertising, and it was how Trump was able to pull this all off without blowing through his own fortune or begging those big donors for cash. He owned the news cycle.

Again and again, he did so, and he was able to do this by disseminating his message outside of the traditional media filter but in a way they could monitor and be baited by.

2. The lack of a GOP standard bearer

The GOP has always been traditional and hierarchical. The nomination went to the person who was "due" (think Bob Dole). That should have probably been Jeb Bush this time around, but Bush was hindered by his own tepid personality and the fact that the country is just too Bush weary. This created a fractured field that gave Trump his opening. What was fascinating was that the ceiling kept rising for him. I’m not sure anyone really predicted that. It’s funny to recount all of the failed arguments, among them that Trump would never break 35 percent. Poor George Will.

3. Chaos in the world and on American streets

It’s a time of great uncertainty and fear. In times of uncertainty and fear, people are more drawn to alpha candidates who project strength. When Trump goes to war with big media or big politics, he looks stronger to people because he’s capable of battling powerful interests. Everything about Trump connotes strength, whether it’s his red tie or his jumbo jet (seriously). It’s all stagecraft, but it works. His lack of political correctness plays to this crowd too; he has the courage to say what others won’t, his supporters think.

4. Simple, memorable slogans

Do you remember what Scott Walker’s slogan was when he ran for president? Me neither. In fact, I can’t remember a single other candidate’s slogan either, and I can’t remember Hillary’s.

Meanwhile, Trump is a marketing genius. "Make America Great Again" is a line that every single American knows and desires the promise of – even if, frankly, it implies we’re not so great now. It’s not that different than the only other recently memorable slogan, "Hope and Change." It dangles a promise in front of people that they desire, albeit a generic one.

In reverse, Trump showed absolute genius when it came to his ability to define his opponents. He’s like a political shark who can zero in on an opponent’s weakness and define it in a boiled-down way that sticks with voters: Lyin’ Ted, Crooked Hillary, weak energy Jeb and so forth. When Trump mentioned that Wisconsin’s budget was kind of a mess, that was it for Scott. Trump is also a master of repetition. He zeroes in on what he wants to say and then he repeats it over and over again.

5. Economic angst

People are struggling. Wages stagnate. Trump promises people a return to affluent times. He evokes the 1980s. That was an era of American exceptionalism and economic affluence. People want that again. They like his business experience, they are fed up with politics as usual and they want the easy opulence he seems to offer. People want Shangri-La.

Will Trump defeat Hillary? I think it’s a coin flip, but I wouldn’t rule him out. The conventional wisdom that he has no chance against Mrs. Clinton could evaporate as quickly as the conventional wisdom that he couldn’t win the Republican nomination (are there any #NeverTrumpers out there anymore?). The terrorist attacks and murders of police officers make people desirous of a security driven candidate who can protect them and restore order.

We will see how the Mike Pence choice for VP plays out. Pence allows Trump to move on from the "he needs to shore up his base" distraction and focus on the Democrat. However, most primary candidates (left or right) move to the middle in general elections. Oddly, in this election, Trump has moved to the right with the selection of Pence. He needed to pin down the base.

Instead, though, he could have made a choice that reached out to Bernie voters. I don’t think Pence does this at all, and his hardcore positions on social issues could be a distraction. But really he ends the distraction of Republican inner drama.

Hillary Clinton is well-funded and formidable, albeit not well-liked. It’s going to be a battle. But I wouldn’t be shocked if we end up with President Trump – and AG Christie, Defense Secretary Mike Flynn, Surgeon General Carson, Supreme Court nominee Cruz, and Secretary of State Gingrich.