Pardons, bullying and purges: Senate Republicans had leverage over Trump but didn't use it

President Donald Trump, emboldened by the acquittal in his Senate impeachment trial, has begun purging the White House and diplomatic service of those who had the temerity to testify about his efforts to coerce Ukraine into boosting his reelection campaign. He publicly bullied the Justice Department into softening its sentencing recommendation for Roger Stone, convicted of lying about his 2016 attempts to get information on damaging Hillary Clinton emails hacked by the Russians. Then came the pardons of wealthy and prominent felons, and the ousting of his acting director of national intelligence.

By these actions, once again, the president is demolishing longstanding practices designed to preserve republican values and prevent the United States from sliding into the sort of strongman rule that Trump admires in other nations. No one should be surprised by these bleak developments, least of all senators who have had front-row seats to Trump's behavior — and one, Susan Collins of Maine, who said the president had learned his lesson from the impeachment process.

It didn’t have to be like this. In 1868, when President Andrew Johnson was facing an impeachment trial in the Senate, Sen. James Grimes of Iowa used the leverage of that moment to win concessions from Johnson for his post-trial behavior. Shamefully, no current senator seems to have known of Grimes’ gambit, much less to have thought of it.

Good conduct or else

In April 1868, Grimes, a Midwestern Republican, was reluctant to convict President Johnson, a Democrat elected on the Republican ticket. Grimes preferred reclaiming the White House in the autumn election. But he also knew that Johnson had a harsh temper and a proclivity for punishing his political enemies. Those backing impeachment warned darkly of a post-acquittal reign of terror at Johnson’s hands.

So Grimes arranged to sit down with the embattled chief executive at a Washington area hotel. The Iowan drove straight to the point. How, he asked, would the president deport himself after an acquittal? Needing Grimes’ vote, Johnson replied that no one should fear his post-trial conduct. He would, he added, comply with the Constitution.

Satisfied with that response — and with Johnson’s agreement to appoint a more acceptable successor to Edwin Stanton as secretary of War — Grimes assured other Republicans that they need not fear acquitting the volcanic president. With the votes of Grimes and six other Republicans, Johnson escaped removal from office by a single vote. And after his acquittal, Johnson indeed measured his actions and statements more carefully than he had before.

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Republican bloc voting in the Senate meant that Trump was never at serious risk of removal from office, but there was a stage when Grimes’ tactic might have been deployed to good use.

Today's Republicans did have leverage

The president was frantic to block Senate testimony from key fact witnesses like former national security adviser John Bolton, White House chief of staff Mick Mulvaney and even Trump's private lawyer Rudy Giuliani. With 47 Democratic senators demanding such testimony, four Republicans would have allowed such testimony. In that situation, four GOP senators certainly could have told the president that they'd support more testimony unless he gave assurances of appropriate post-trial conduct.

Not only did no other Republican join Collins and Sen. Mitt Romney of Utah in voting for witness testimony, but no Republican even tried to secure commitments from the president for his post-trial conduct.

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Did today’s senators have enough leverage over the president to win such commitments in return for scuttling witness testimony? The president’s blizzard of tweetstorms on that issue suggests that the answer is yes. Shamefully though, we will never know: We still do not know what those witnesses would say, nor did any senator have the wit or the backbone to employ the approach used by Sen. Grimes.

Chalk up one more depressing failure by today’s Senate.

David O. Stewart is the author of "Impeached: The Trial of President Andrew Johnson and the Fight for Lincoln’s Legacy" and other works of history.

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This article originally appeared on USA TODAY: Impeachment: Republicans could have tried to rein in Trump but didn't