It is now official. Seventeen candidates ran for the Republican presidential nomination, and the sixteenth of these just suspended his campaign. This leaves Donald Trump as the last man standing. A whole lot of people who never thought we'd arrive at this point are now going to have to get used to the phrase: "Donald Trump, Republican nominee."

Before we get to that, a quick look back is necessary to see how we got here. The 2016 Republican field was supposed to be the most impressive in recent memory -- that's the starting point, really. There were seventeen major candidates running, after all. They had senators, governors, outsiders, insiders -- all supposedly showing how deep the Republican bench truly was. There was even a dynastic candidate on the ballot, who many assumed (very early on) was going to sweep away all others and become the third Bush to run in living memory.

One by one, they fell away. Rick "Oops" Perry was the first to go, followed quickly (and surprisingly) by Scott Walker, who was supposed to be one of the favorites from the establishment Republican ranks. Next to go were Bobby Jindal and Lindsey Graham, both of whom seemed rather shocked at how well Trump was doing in the early contests. The next round of exits were mostly candidates with only minor support at best: George Pataki, Mike Huckabee, and Rand Paul. Paul and Graham were the first to make a real effort to take on Trump with full-frontal attacks, but they immediately sank in the polls as a direct result. Rick Santorum and Carly Fiorina soon followed the same path. Chris Christie was the next to go, and it's hard not to feel at least a little bit sorry for him, since he was supposed to be the loud-mouthed, brash, urban type of candidate -- before he was totally eclipsed in this regard by Trump. Christie then threw his lot in with Trump in noticeably sycophantic fashion, in the hopes of (perhaps) becoming Trump's running mate. The next to exit the contest was Jim Gilmore, which came as a surprise to most people, because they weren't even aware he was running. The twelfth candidate to go was a real political earthquake, though, because Jeb Bush was billed as the one who could clear the entire Republican field. Bush spent an absolute fortune (of other people's money, naturally), and wound up with only single-digit support from the voters -- which shocked the Republican establishment to its very core. Ben Carson and Marco Rubio then both exited after poor showings (Rubio only won a single county in his home state, which was truly embarrassing). Which brings us to the past two days, where after Trump's commanding win in Indiana first Ted Cruz and then John Kasich became the last to regretfully throw in the towel.

Sixteen candidates tried, and the only ones to even lay a glove on Trump were Ben Carson (early on, before the primaries started), Marco Rubio (who won Minnesota, Washington D.C., and Puerto Rico), and John Kasich (who won his home state of Ohio). The only one to even realistically challenge Trump's dominance was Ted Cruz, who won a number of states but trailed badly in the delegate count. I kind of doubt Kasich or Carson will run again next time around, but I fully expect to see Rubio and Cruz try again. Something few are noting now is that the strategy Cruz developed early on actually worked -- Cruz refused to attack Trump for months, and actually defended some of Trump's more outlandish positions. While all the Trump attackers collapsed at the polls, Cruz was the only one who lasted long enough to actually challenge Trump's delegate dominance. By avoiding the early fights with Trump, Cruz made it further than anyone else.

But now they're all just footnotes in the history of the 2016 election. Donald Trump is going to be the Republican Party's nominee for president. This prospect was dismissed out of hand early on, with pretty much everyone in the media convinced that "he'll flame out -- it's inevitable." From that point, they moved quickly on to convincing themselves "Trump doesn't have real voter support -- nobody's actually going to vote for him." There was massive speculation about Trump eventually running as a third-party candidate (which even gave rise to a GOP "loyalty oath"), because of course he couldn't ever actually win the nomination outright. After the voting started and Trump began racking up state after state, the pundits all went wild predicting an open or brokered convention. Much ink was spilled (and many pixels and photons wasted) over how this was all going to play out -- would Cruz win on the second ballot or would Paul Ryan ride in on a shining white horse on the third ballot to save the party? Even this late in the game, nobody could quite believe the numbers -- Trump was still (of course) somehow going to stumble badly, since (obviously) he simply could not win the nomination of the Grand Old Party of Abraham Lincoln.

All this wasted speculation is now over. All the hopes and dreams of open conventions now lie dead in the Indiana dust. The "Never Trump" faction is huddling in mourning, left only with two rather pathetic options. They can now spend all their time, energy, and money working to distance other Republicans (Senate candidates, mostly) from their own party's nominee, or they can mount a futile third-party bid of their own, which would certainly be doomed to failure.

That last option is likely going to generate just as much enthusiastic speculation from the inside-the-Beltway pundits as the open convention concept has been for the past few months. It's shocking that we even find ourselves at this point, but what some establishment Republicans are now contemplating is for the Republican Party establishment to leave the Republican Party and launch a third-party bid for the presidency. Trump's takeover of the party is now complete, and they are the ones left out in the cold, not Trump. While this will be fun for everyone to speculate about for a few weeks, the reality is that it will be nigh on impossible to recruit any hapless sacrificial lamb to run on such a bizarre ticket. Who in their right mind would favorably react to an offer to mount a presidential bid that is sure to lose, just to save some dignity for the Republican establishmentarians and perhaps avoid a total down-ballot slaughter? That's not exactly a tempting job offer, to put it mildly. Maybe the establishment Republicans will steal a page from Michael Moore's playbook, and run a ficus plant for president on a third-party ticket -- because at this point, it seems like that would achieve the same desired result as having an actual living, breathing human being atop their third-party ticket.

My guess is that there will be a lot of noise about a third-party bid, and then it will all fade into the woodwork as the big Republican donors begin focusing on an attempt to salvage their Senate prospects. This was always going to be a tough row for them to hoe in any case, because of the number of vulnerable Republicans up for re-election this time around (we are six years from the Tea Party blowout of 2010, and a lot of the Republicans who won back then haven't lived up to their promises). My guess is also that the "Never Trump" movement itself will soon collapse, much as the "Party Unity My Ass" (PUMA) group did back in 2008, on the Democratic side.

At this point, the biggest thing Trump has going for him in the general election is that he is not Hillary Clinton. That may sound snarky, but it is true. There will likely be millions of people who turn out to vote for Trump in November who can't stand the thought of him becoming president -- but who also can't stand the idea of President Hillary Clinton even more. To put this another way, the Republican Party will likely unite against Hillary, instead of rallying in a positive way behind Trump. So, in the end, party unity might be achieved even with Trump as the nominee, which few would have ever predicted even a few weeks ago.

None of the other Republican candidates' attacks on Trump worked. That should be at least a little bit worrisome for Democrats, but the general election campaign is going to be profoundly different than the Republican primary season. Most Republican candidates were downright envious of the public support Trump consistently showed in the polling among Republican primary voters, which led them to pull their punches on Trump. They had to walk a tightrope of somehow tearing down Trump without completely alienating his followers. None achieved this impossible task, of course. But Hillary Clinton will be operating under no such constraints. Clinton knows full well that the die-hard Trump fans are just never going to vote for her, so she won't be concerned with alienating them at all. She's not going to pull any of her punches, that's for sure.

Donald Trump is going to be the Republican Party's nominee for president. The only remaining question, really, is who he'll name as running mate. We'll all have plenty of time to speculate about that in the coming weeks (my guess, at this point, would be either John Kasich, assuming Trump can convince him to be on his ticket, or Newt Gingrich). But all the rampant speculation about Trump's eventual flaming out, Trump's possible third-party bid, whether Trump voters would actually turn out, and (last but not least) a brokered GOP convention is now all completely over.

Donald Trump won a triumphant victory last night in Indiana. His remaining two GOP challengers have now dropped out. Trump has won the primary race. It's over. Astonishing as it now may seem, just like every other pundit out there, I am now going to have to get used to typing the phrase: "Donald Trump, Republican nominee."

-- Chris Weigant

Cross-posted at The Huffington Post

Follow Chris on Twitter: @ChrisWeigant