Jonathan Ernst / Reuters

In late June 1973, Republican Senator Howard Baker of Tennessee earned his place in history by asking the essential question of the Watergate hearings: “What did the president know and when did he know it?”

Baker had been a Nixon ally. In February 1973, he told Nixon, “I’m your friend. I’m going to see that your interests are protected.” But that was before the revelation that Nixon had recorded Oval Office conversations, and before White House Counsel John Dean diagnosed the presidency with “cancer.” The changing Watergate dynamics changed Baker.

You don’t need to be an oncologist to figure out that the country is suffering from a recurrence of the same disease. We have another president under investigation, one accused of high crimes, misdemeanors, and everything in between. What we don’t have is another Baker. No one in the GOP has shown readiness, as the saying goes, to put country before party.

John McCain is dead. Lindsey Graham has gone MAGA. Susan Collins never lives up to liberal fantasies. And Mitt Romney is Mitt Romney; his naked ambition and political opportunism make him a less-than-ideal protagonist. But Democrats can’t take on the president alone. A recent ABC News/Washington Post poll found that although a majority of Americans support investigating President Donald Trump, a significant portion—46 percent—believe that any process conducted by House Democrats would be unfair.

Only one Republican senator might shift from protector to prosecutor, as Baker did, and bridge the trust gap: Baker’s protégé, Lamar Alexander of Tennessee.

As Alexander’s former student and speechwriter, I can attest to the senator’s rectitude. Democrats set on impeachment should realize that Alexander is their pressure point. He was made for this moment, in part because he made his career in Baker’s image.

Alexander served as Baker’s first legislative aide, in 1966, and worked again for him in the late ’70s. Like Baker, Alexander has unassailable party bona fides. He is regularly endorsed by the National Rifle Association, the National Federation of Independent Business, and the National Right to Life Committee. And he has bipartisan credentials, too. He and the Democratic Senator Patty Murray of Washington worked on medical research, education, and opioid addiction as the Senate leaders of the Committee on Health, Education, Labor, and Pensions. The two made a valiant attempt at fixing the Affordable Care Act. Murray, Minority Leader Chuck Schumer, and other Democrats have spent time at Alexander’s cabin in the Smoky Mountains.

This way of doing business descends directly from Baker, who liked to quote his father as saying, “You should always listen to the other fella. He might just be right.” Alexander shares Baker’s talent for “eloquent listening,” a phrase Alexander used when he eulogized his mentor in 2014.

For all their similarities, Alexander has eclipsed Baker. Alexander was a popular two-term governor, university president, U.S. secretary of education, and presidential candidate. But his ability to talk about the country with the country is what truly separates him from other political leaders. A jaded Harvard grad student, I was surprised to find myself inspired when a conservative from East Tennessee connected the intricacies of election reform to the national narrative and the strengths of the American character. With candid optimism, he bridged our differences.

Alexander has the stature to help Congress and the country navigate through possible impeachment and removal proceedings. And, as luck would have it, he’s retiring at the end of his term, so he doesn’t have to worry about repercussions from the still Trump-infatuated Republican base.

Of course, the fact that Alexander is right for the job doesn’t mean he wants it. In recent interviews, he has dismissed the idea that retirement offers a chance to play a mediating role in Washington. “They took Trump and they didn’t take me,” he told Vox.

Democrats looking for an ally should ignore that quip, which undersells his five decades of service. Instead, they should look to Lamar Alexander’s Little Plaid Book, the paperback he published in 1998 that describes his 311 rules for living.

In it, he tells a story about a Dwight D. Eisenhower Cabinet meeting. It was rife with indecision. Each secretary was protecting his particular interest. Ike nearly lost his cool. The president finally boiled the chaos down to one essential question, which became Alexander’s Rule 151.

“When stumped for an answer, ask yourself, ‘What is the right thing to do?’ Then do it.”

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