History is on Trump’s side.
Historically, whoever led the field in December went on to win the nomination.
What is impressive in the past year, is the remarkable stability of the race.
Unlike in 2008 and 2012, where the lead changed hands several times, Trump has been dominant since he entered the race in the summer.
If it was Jeb, every one would be writing its all over but with Trump they still hope somehow he will implode.
That won’t happen and facts are stubborn things.
When was the last time there were 5 candidates (or more) with a chance of earning 5% or more of the vote in a proportional caucus/primary state? Do you see Bush, Christie, or Kasich dropping out before South Carolina? Do you see Carson or Fiorina dropping out before New Hampshire?
Furthermore, there’s a reason we say “ground game matters”. Ground game is not just getting folks to the caucus/voting booth. It is making sure you have precinct captains and delegates who support your candidate. Why? Because:
“If a presidential candidate has received a share of the delegates as a result of the presidential primary but withdraws as a presidential candidate at any time prior to the convention, his pledged delegates shall be released by the candidate and each delegate is free to support any candidate of his political party who may be his choice as a candidate for president. [RSA 659:93 VI]”
http://www.thegreenpapers.com/P16/NH-R#0209
That means that even if Trump wins 40% of the New Hampshire delegates, the other 60% can, when their candidate drops out, chose whoever they want. That’s why you have to have “ground game”: getting your candidate’s solid supporters involved in the delegation.
Trump wins Iowa in an absolute blowout, attracting many first-time caucus-goers and new Republicans.
He has translated the army of enthusiastic supporters into actual votes and growth in the party.
The establishment knocks each other down rushing to get on the Trump train.
The race is effectively over after New Hampshire.