Here we are, barely a week into the Trump administration, and half of the country that opposed him during the election is quivering with rage. He’s building the wall! He’s banning immigration from some Muslim countries! He’s wrecking ObamaCare! He’s sacking top officials at the State Department! He’s threatening sanctuary cities! What’s going on here?

It’s called: keeping his campaign promises.

The answer is simple: we’ve become so inured to politicians lying to us to get elected that we find it hard to believe that the new man in the White House actually meant what he said — and can’t wait to get on with it.

Not since the heyday of Ronald Reagan have the Democrats been in such shock and disarray. First, they — and their “never Trump” collaborators on the right — said he’d never get the nomination. When he did, they assured themselves there was no way he could beat the Hillary Clinton juggernaut so beloved of the media, the insulated superrich and the dependent class.

Whoops!

That all changed on Nov. 8. Of course, they’ve reacted to the upending of their fantasy world with petulance, threats, marches, actual violence and lawfare. Indeed, a few dead-enders calling themselves the Citizens for Responsibility and Ethics in Washington filed suit last week charging the nation’s First Businessman with violations of the emoluments clause in the Constitution, which forbids US office holders from accepting things of value from foreigners.

Never mind that with that provision the Founders were trying to prevent officials from profiting from high office via bribes or blandishments; or that Trump has relinquished control of his real-estate businesses; and that his income prior to becoming president had nothing whatsoever do with the presidency. If it’s emoluments you’re seeking, check out the Clinton Foundation.

The cries of ‘You can’t do that!’ are beginning to abate as Americans realize that, in fact, yes we can.

Even for some conservatives, the vigorous pace at which Trump is taking action is disorienting.

George H. W. Bush squandered the fruits of the Reagan revolution and the end of the Cold War in his pursuit of a “new world order” and a duel with Saddam Hussein. His son talked a good game about immigration and terrorism but finished neither the fence Congress explicitly authorized in 2006 nor the wars in Iraq and Afghanistan.

Even Reagan never abolished the education or energy departments, as he promised.

While Trump’s actions so far are mainly symbolic — he still has to flesh out his Cabinet, push Congress to appropriate monies to begin construction and hire the diggers and masons for the wall — he’s already given his supporters hope that this time, things just might be different.

And that’s what has everyone in the country in such an uproar. After 65 years of government by the congressional Permanent Bipartisan Fusion Party, Americans now confront the brave new world of a president who will cut through the red tape and make change happen.

Half of America — the coasts and the big cities — is apparently shocked by Trump’s eagerness to start delivering on the promises that got him elected in the first place. They’re not used to a politician who not only means what he said on the campaign trail, but also is not dissuaded by the usual recalcitrant Washington bureaucracy, media nitpickers and congressional back-scratchers.

Doesn’t he know how the game is played? That the rule is to wink at the rubes who make up your base, then quickly join the insider’s game. After all, Republicans like the horse-trading majority leader Mitch McConnell and senator John McCain have fashioned entire careers out of promising their constituents one thing and delivering their big donors something altogether different. Surely, D.C. will corrupt Trump the way it has most everybody else.

Worst of all, they can’t believe the other half of America is actually cheering Trump on as, on one hot-button issue after another, he’s giving them exactly what they voted for, at warp speed.

First signs are they like it. Decisiveness has always been a prized quality; a recent Rasmussen poll put Trump’s approval rating at 59 percent and rising (although others have him as low as 36). The cries of “You can’t do that!” are beginning to abate as Americans realize that, in fact, yes we can.

So what’s next? Look for the new Pentagon chief to quickly begin hitting ISIS harder. Look for a humane but effective evaluation of Obama’s permissive policy toward “Dreamers” — children of illegal aliens whose sob stories have passed their sell-by date. Look for sanctuary cities to come to heel as Trump’s threats to cut federal funds start to bite. (On Wednesday, Miami-Dade’s mayor announced a new policy of cooperation with Homeland Security regarding so-called “detainer” requests, which the county up until now had been refusing for financial reasons.) Look for more housecleaning at State and elsewhere as the swamp drains and the number of undersecretaries dwindles.

And maybe, just maybe, look for a new attitude from the media if it wants to stay relevant: tough but fair.

What do you mean, he can’t do that?

Michael Walsh is an author, screenwriter and contributing editor at PJ Media. His most recent book is “The Devil’s Pleasure Palace.”