The October surprises are in.

The Access Hollywood tape knocked Donald Trump off his game for two weeks. James O’Keefe and Project Veritas exposed the thuggery and lawlessness at the core of the Hillary Clinton campaign. And Wikileaks provides daily evidence of the Clintons’ pathological corruption.

But the biggest shock of all has been the dramatic increase in Obamacare premiums.

I use the word “shock,” and not “surprise,” because the sharp rise in prices — double- and triple-digit percentages, in many states — was predictable.

Republicans had been warning about it since 2009. Young, healthy people will refuse to overpay for insurance they do not need. The remaining patients will be older and sicker. Prices will have to rise. More patients will drop coverage. And then, collapse.

Thanks to the provisions of the Obamacare statute itself, many of the law’s most obnoxious deadlines happen in the fall, right in the middle of election season.

The White House tried to defer as many of the mandates as it could, effectively re-writing the law and violating the Constitution for purely political reasons.

But the deadlines could not be deferred forever. And Hillary Clinton can do nothing about them.

If Donald Trump manages to pull off an upset victory in November, it will be because of Obamacare.

He mentioned it at every single campaign stop on Wednesday (though, typically, the media focused on his comments about Newt Gingrich and Megyn Kelly, who evidently are more newsworthy than the ongoing destruction of the American health care system). He will doubtless slam Obamacare every day until Election Day.

Most analysis of elections is speculative at best. There are millions of variables, and only one data point (win/lose). But if you had to choose one factor to describe recent American political fortunes, you could do worse than choosing Obamacare.

It fueled the Tea Party revolt of 2010, after Nancy Pelosi (D-CA) told Congress to pass it so America could found out what was in it.

It also propelled Republicans to victory in the 2014 midterm elections. When Sen. Ted Cruz (R-TX) tried to block Obamacare from taking effect in 2013, setting off a confrontation with the White House and a shutdown of the federal government, analysis predicted a disaster for the GOP in the midterms. Instead, voters gave Republicans a majority, hoping they would use it to finish what Cruz had started.

In 2012, Obamacare was also a factor — in Mitt Romney’s loss, after Republican voters deferred to the wisdom of the party establishment and nominated a candidate whose opposition to Obamacare had zero credibility.

(In his official gubernatorial portrait, which was unveiled at the Massachusetts State House during the 2012 campaign, Romney made sure his health law was depicted on the desk.)

Now, in 2016, Obamacare’s premium increases may propel voters to the polls to punish the party that bears sole ownership of the policy.

But there are other reasons Obamacare is such a potent factor.

It is a reminder, for example, of how brazenly President Obama lied to the American people, promising them that they would save money — and that they could keep their insurance plans and their doctors.

Obamacare also corrupted every branch of the federal government: the legislature, which passed the law through the Senate on a plain majority vote, thanks to a budget “reconciliation” trick; the judiciary, which agreed that the individual mandate was unconstitutional but rewrote the penalty as a “tax”; and the executive, which not only overstepped its authority but also botched the launch of healthcare.gov.

The law also destroyed public trust in government. When Democrat operative Robert Creamer, sitting in federal prison, began working on the strategy for passing “universal health care,” he conceived it as the first of a series of radical changes that Democrats could enact.

Once the public had become used to that kind of systemic overhaul, it would resist each new change — immigration, gun rights — less.

The opposite happened: the public rejected Obamacare, and rejects it still.

Barack Obama’s unique achievement — if it can be called that — was to stick with Creamer’s plan anyway, and to attempt by executive fiat what the left had once hoped to do through popular consent.

Only the nation’s first black president could have done something so audacious, and survived the political consequences.

Now Hillary Clinton is running on a promise to “fix” Obamacare.

That is the essence of the choice the voters face: whether to accept a failing status quo, with feeble promises for minor reforms; or to risk abrupt interventions by an untested outsider.

Before the Obamacare premium spikes, one of those choices had looked much more likely.

But now, Trump is still in the race, thanks to the October-suprise-that-wasn’t.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new book, See No Evil: 19 Hard Truths the Left Can’t Handle, is available from Regnery through Amazon. Follow him on Twitter at @joelpollak.