Norman J. Ornstein is a resident scholar at the American Enterprise Institute and the author, with Thomas E. Mann, of “It’s Even Worse Than It Looks: How the American Constitutional System Collided With the New Politics of Extremism.”

I met Tom Korologos in 1970. I was doing interviews for my dissertation on congressional staffs; he was the top staffer for Wallace Bennett, a veteran Republican senator from Utah. Tom not only granted me an interview but also gave me a ton of time and valuable insights. He knew and loved the Senate, knew and loved politics. He has had a remarkable career in Washington, serving several Republican presidents and also working as a top official with the provisional authority in Baghdad and as ambassador to Belgium. If you asked me to name veteran pols who understand how our government and politics work and should work, he would be high on the list.

That makes my disappointment with him even more painful. Korologos, along with former Ronald Reagan national security adviser Richard V. Allen, wrote an op-ed for The Post last week with advice for their fellow Republicans, headlined “Memo to GOP: Forget 2016. Start thinking 2018 and 2020.” The op-ed conceded the presidential contest to Hillary Clinton — and proceeded to give advice on how to combat the incoming president and regain the party’s mojo.

What I would expect from someone of Korologos’s character — and that of Allen — is a list of ways to recapture for the GOP its identity as a conservative, problem-solving party: how to find common ground that solves pressing national problems and does not violate fundamental principles; how to compromise in ways that will move the country away from its precarious position — in a political system now caught in the cross hairs of tribal partisan warfare, stuck in obstructionist limbo, and facing growing racial and ethnic tension.

What we got was something else. The core of their advice to Republican lawmakers was to double down on the obstructionist approaches that have defined the Obama years, and to do the same with the kind of “gotcha” investigations that delegitimize a president and Washington politics, while using delay tactics and filibusters to block Clinton Supreme Court nominees.

We know that Republican congressional leaders, on the night of President Obama’s inauguration in January 2009, chose a deliberate policy of uniting in opposition to all of his initiatives, even before he served a full day in office. Now we have a pair of blue-ribbon establishment Republicans fundamentally suggesting the same approach — one that has contributed to the decline of the Republican brand, the rise of Donald Trump, the weakening of GOP leadership and the growth of know-nothing radical anti-government sentiment — months before the election of a president.

To be sure, that delegitimizing approach had big payoffs in the historic midterm gains of the Republican Party in 2010 and 2014. Hamstringing government while trashing any policies that actually get enacted almost inevitably works against the party of the president, which is held responsible for action and inaction in Washington. And the same approach might well pay off in 2018.

But the strategy backfired in the presidential contest in 2012 and has helped create the disaster the party faces this year. And the price the country, and the party, will pay will be fearsome. The challenges facing the United States are real and broad. Our infrastructure is crumbling, and the cost of replacing aging water and sewer systems once they collapse will be sharply greater than acting now. The same is true of the lock and dam system, mass transit, bridges and other transportation systems. The electrical grid needs both modernization and hardening to combat cyberterrorism that could shut the country down. Finding ways to enable people who do their part, working hard to support their families, to have roofs over their heads, food on the table and a safety net against an illness, accident or other disaster is a key to our social contract.

The Affordable Care Act needs the technical corrections that every other major social policy received after its passage, and some adjustments, including conservative and market-driven ones, to make it work better. We need to address prison reform, immigration, policy toward serious mental illness, the broader issues of our tax system. If there is no Trans-Pacific Partnership and no broader European trade deal, we need a serious, bipartisan effort to craft a new trade regimen that does not jeopardize the U.S. and global economies. We need to think hard about how we confront terrorism, including funding for homeland security and a much stronger counter-cyberterrorism program.

That is a partial checklist of issues that need action by Congress in conjunction with the president and in the way — via debate, deliberation and compromise — the framers envisioned our system working. Focusing on short-term tactical gains instead of building a problem-solving party and attending to the pressing needs of the nation should be the purview of ideologues and partisan hacks, not veteran Washington actors. If that mind-set prevails, even if it reaps rewards in 2018, the nation will suffer — and ironically, it will likely leave the Trump and Ted Cruz forces positioned to lead the party in 2020.