Back in 1999, I spent a long day tooling around Iowa with Lamar Alexander. At the time of our travels in a Winnebago, accompanied by a couple of aides and a press corps consisting of me and an AP photographer, he was a former Tennessee governor and a presidential candidate trying to compete with the rock star campaign of George W. Bush.

What I remember most from that day was a dramatic back story that, to my puzzlement, he did not mention in his pitch to voters. President Bill Clinton had been impeached by the House and tried in the Senate in a consuming saga of sex, lies and investigations. Voters seemed ready for someone of, as they say, unimpeachable character. Enter Alexander, at least theoretically.

Who would be more perfect for the moment than a man who had taken over a state amid a gubernatorial pardon-selling scandal so serious that he was sworn in three days early in a secret 1979 ceremony, to cut short outgoing Gov. Ray Blanton’s corruption spree? So sensational they made a movie about it, called “Marie,” in which a lawyer (and future senator) named Fred Thompson played himself? The obvious narrative was that Alexander knew how to restore trust in government — he had already done it in Tennessee.

Just another cowering Republican

Alexander never became president, but in 2002, he was elected to his first of three terms in the Senate. He was known in Washington for pragmatic bipartisanship — a senator who quit leadership in 2011 so he could work across the aisle more often, and who made good on that most recently in partnership with Sen. Patty Murray, D-Wash., on education and health policy.

Now Alexander's just another Republican cowering at the prospect of crossing President Donald Trump, one of the many people I don’t recognize despite having covered and followed them for years or even decades.

Sen. Lindsey Graham of South Carolina is another. We first met on Sen. John McCain’s 2000 presidential campaign, when Graham and Thompson were all in with the McCain brand of “straight talk,” rebellious independence and cross-party relationships.

There’s also Florida’s Marco Rubio, who was instrumental (with Graham) in getting a landmark bipartisan immigration bill through the Senate in 2013. Alaska’s Lisa Murkowski, whose primary loss to a Tea Party candidate in 2010, and subsequent win as a write-in candidate, should have meant she’d never owe her party anything, and who played key roles in bipartisan negotiations I wrote about in “The Art of the Political Deal.” There’s even Susan Collins, who with her moderate Maine colleague Olympia Snowe was so notorious in conservative circles for occasionally going her own way, she evinced disgust from an Arizonan fed up with both McCain and "those two women who vote with the Democrats all the time."

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These politicians are now strangers to me. Their whole party is untethered — not just from reality and its own history, but also from the Constitution itself. I found three pocket copies of it in a drawer the other day and was reminded of how well I’ve gotten to know it these past few years. After this, there will be no way to take seriously any GOP argument that relies on the “original intent” of the Constitution.

I have no doubt many Republicans will try to deploy it, especially in defense of gun rights. But I ask you, what has changed more since the 18th century, the existence of foreign powers who’d love to weaken us and the potential for a president who has no problem selling us out, or easily available weapons of war in a country of 329 million?

A union on the verge of failure

There’s no contest. The Founders never could have foreseen the invention of semiautomatic weapons or the millions now in private hands. But they well understood "the dangers from foreign force and influence" and warned about them repeatedly — in the Constitution and in Federalist Papers Nos. 2, 3, 4 and 68, for a start.

They also were all too familiar with "the misconduct of public men," as Alexander Hamilton put it in Federalist 65, which is why the Constitution includes an impeachment option.

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For the 40 years I have written about politics, there has been something to like or respect about nearly every politician I've encountered. Even when I passionately disagreed with someone on tax or gun or war policy, there was always at least one thing: They welcomed immigrants, wanted to save the planet or were willing to defy elements of their own party to seek a "grand bargain" on taxes and spending. Maybe they were dishonest and had to resign in disgrace, but not before creating the Environmental Protection Agency and the Occupational Safety and Health Administration.

Lately, the Founders have also been top of mind. Many of the most prominent owned slaves, and it's hard to get past that, even considering their times. But they also laid what they hoped was a permanent foundation for an aspirational nation striving toward its ideals. They clearly anticipated and feared someone like Trump, and tried to give us the remedies and protections we'd need.

Those safeguards have failed. Let's hope the union the framers envisioned doesn't fail, as well.

Jill Lawrence is the commentary editor of USA TODAY and author of "The Art of the Political Deal: How Congress Beat the Odds and Broke Through Gridlock." Follow her on Twitter: @JillDLawrence