Anyone still unsure of how (or even whether) they’ll vote in the midterm elections should consider this: All three branches of government are now under the control of one party, and that party is under the control of Donald J. Trump.

With the addition of Brett Kavanaugh, the Supreme Court is as firmly Republican as are the House and Senate.

Kavanaugh was revealed as a fierce partisan. He is not only the legal adviser who helped Kenneth Starr prosecute Bill Clinton and almost certainly guided George W. Bush’s policy on the torture of detainees, but also a nominee who believes “leftists” and Clinton sympathizers are out to get him.

He joins four other Republican-appointed jurists who are just as partisan. Clarence Thomas, Samuel Alito and John Roberts have never wavered from Republican orthodoxy. Neil Gorsuch, although without much of a track record on the Supreme Court to date, was a predictable conservative Republican vote on the 10th U.S. Circuit Court of Appeals — which is why the Heritage Foundation pushed for him and Trump appointed him.

Even under normal circumstances, when all three branches are under the control of the same party we get a lopsided government that doesn’t respond to the values of a large portion of the electorate.

But these are not normal circumstances. Donald Trump is president.

Need I remind you? Trump is a demagogue who doesn’t give a fig for democracy; who continuously and viciously attacks the free press, Democrats, immigrants, Muslims, black athletes exercising First Amendment rights, women claiming sexual harassment and anyone who criticizes or counters him; who treats the executive branch, including the Justice Department, like his own fiefdom and brazenly profits off his office; who tells lies the way other people breathe; and who may well have conspired with Russian President Vladimir Putin to swing the election his way.

Trump doesn’t even pretend to be the president of all the people. As he repeatedly makes clear in rallies and tweets, he is president of his “base.”

And his demagoguery is by now unconstrained in the White House. Having fired the few “adults” in his Cabinet, Trump is now on the loose (but for a few advisers who reportedly are trying to protect the nation from him).

All this would be bad enough even if the two other branches of government behaved as the framers of the Constitution expected — as checks and balances on a president. But under Republican leadership, they refuse to play this role when it comes to Trump.

House and Senate Republicans have morphed into Trump sycophants and toadies — intimidated, spineless, opportunistic. The few who have dared call him on his outrages aren’t running for re-election.

Some have distanced themselves from a few of his most incendiary tweets or racist rantings, but most are obedient lapdogs on everything else — including Trump’s reluctance to protect the integrity of our election system, his moves to prevent an investigation into Russian meddling, his trade wars, his attacks on NATO and the leaders of other democracies, his swooning over dictators, his cruelty toward asylum-seekers, and, in the Senate, his Supreme Court nominees.

Senate Majority Leader Mitch McConnell has emerged as Trump’s most shameless lackey, one who puts party above nation and Trump above party. The House leadership is no better. Devin Nunes, chairman of the House Intelligence Committee, is Trump’s chief flunky and apologist, but there are many others.

Now that Kavanaugh is on the Supreme Court, you can forget about the court constraining Trump, either.

Kavanaugh’s views of presidential power and executive privilege are so expansive that he would likely allow Trump to fire special counsel Robert Mueller, shield himself from criminal prosecution and even pardon himself. Kavanaugh’s Republican brethren on the court would probably go along.

So how are checks and balances, a constitutional imperative, to be salvaged when they’re so urgently needed? The only remedy is for voters to flip the House or Senate, or ideally both, on Nov. 6.

The likelihood of this happening is higher now, with Kavanaugh joining the Supreme Court and Trump so manifestly unchecked. Unless, that is, enough voters have become so demoralized and disillusioned that they just give up.

If cynicism wins the day, Trump and those who would delight in the demise of American democracy (including, not incidentally, Putin) will get everything they want. They will have broken America.

For the sake of the values we hold dear — and the sake of the institutions of our democracy that our forbearers relied on and our descendants will need — this cannot be allowed.

It is now time to place a firm check on this most unbalanced of presidents and vote accordingly.

© 2018 By Robert Reich

Robert Reich, a professor of public policy at UC Berkeley, is the author of “The Common Good.” To comment, submit your letter to the editor at SFChronicle.com/letters.