No, Mr. Trump, You're Not the Presumptive Nominee... Yet

In his victory speech after winning all five of the Northeast primaries on Tuesday, Republican frontrunner Donald Trump declared himself the "presumptive nominee." As much as his fans liked it, the statement is, strictly speaking, just not true.

Despite big wins in Connecticut, Delaware, Maryland, Pennsylvania, and Rhode Island, The Donald still lacks the 1,237 delegates required to secure the nomination. It is true that his last remaining challengers, Ted Cruz and John Kasich, cannot gain enough pledged delegates to win outright, but that does not mean that Trump wins by process of elimination. The Donald cannot assume he wins just because his competition cannot claim the crown -- he still has to pass the finish line himself.

That said, Trump is roughly on track to win the nomination. Even if Ted Cruz defeats him in the must-win states of Indiana and California, The Donald will only be about 100 delegates short. This is the scenario necessary to push the race to a contested convention, but even that does not guarantee a Cruz victory.

The Texas senator has the strongest grassroots operation focused on electing delegates who are friendly to Cruz. This is a brilliant strategy, so long as it does not distract from winning the two remaining states to block Trump's nomination. On the first ballot at the convention, all pledged delegates will have to vote in the way their states decided. These are the raw numbers you see everywhere: Trump 950, Cruz 560, Kasich 153. After the first ballot, those delegates can start to decide for themselves.

As Nate Silver pointed out, "Delegates are people!" While they are pledged to support the winner in their state or congressional district for a time, eventually they will be free to back anyone. This is why it matters who the delegates actually are. This is the game Cruz has been winning, to a certain extent. But he has to win this game big, and I mean really big, in order to clinch the nomination on the second or third ballot.

If the convention moves beyond a third ballot, all bets are off. At this point, John Kasich -- or even a dark horse like Paul Ryan or Mitt Romney -- will start to look appetizing to delegates, or they might just go back to the devil they know and back The Donald. With Paul Manafort, the political wrangler who got Vladimir Putin's man elected in Ukraine, Trump's campaign might just recapture the wind after a few bad votes.

Next Page: The reasons why Republicans should fight Trump to the bitter end.