History tells us it is unlikely that President Trump will be impeached and removed from office, although the odds may increase when the 116th Congress convenes in January 2019.

Efforts to find a way to remove Trump from office began almost immediately after he took office, then it moved from left-wing social media to mainstream telecasts and publications and the halls of Congress after Trump fired FBI Director James Comey on May 9. 


Four days later, the prominent Democratic constitutional scholar, Laurence Tribe, argued in The Washington Post that the Comey firing constituted obstruction of justice — an even worse “high crime and misdemeanor,” he argued, than the ones that drove Richard Nixon from office in 1974 because it “involved national security matters vastly more serious than the ‘third-rate’ burglary that Nixon tried to cover up in Watergate.”


Only two of Trump’s 44 predecessors — Andrew Johnson in 1868 and Bill ClintonWilliam (Bill) Jefferson ClintonFox News poll: Half of Americans say Trump should be convicted and removed Sunday shows - Spotlight shifts to Trump tweet, Senate trial witnesses Fox's Wallace confronts Dershowitz with clip arguing crime not necessary for impeachment MORE in 1998-1999 — have been impeached by the House of Representatives. Neither was removed by the Senate. A third, Nixon, resigned in the face of certain impeachment and removal. 

Four factors that account for the varying ways Congress dealt with the Johnson (a very close call), Nixon (a clear rejection) and Clinton (close in the House, not in the Senate) impeachment controversies could apply today. 

As might be expected from a process that entrusts impeachment and removal to elected officials, partisan politics is one factor. An overwhelmingly Republican Congress (191-46 in the House and 42-11 in the Senate) impeached and came within one vote of removing the Democrat Johnson. A solidly Democratic Congress (242-191 in the House and 56-42 in the Senate) forced the Republican Nixon to resign. And a strongly Republican Congress (226-207 in the House, 55-45 in the Senate) impeached but did not remove Clinton, a Democrat. 

A Congress controlled by the opposition is a necessary but insufficient condition for impeaching a president. Most recent presidents have faced such a Congress for at least part of their time in office without being impeached. 

A second factor is the president’s standing with the voters. Even without polls to measure how unpopular Johnson was, the results of the 1866 midterm election made clear to his contemporaries that he had little public support. Nixon’s job approval rating in the Gallup Poll sank below 30 percent in late 1973 and stayed there. 

Clinton’s case is more complicated. His party actually gained five House seats in the 1998 midterm, the first time this happened during a president’s second term since 1822. His job approval rating remained above 60 percent during the entire controversy, soaring to 73 percent in December 1998 when the House was voting to impeach him.  

House Republicans feared their chamber’s party leaders, who were determined to force Clinton out, and were motivated by their knowledge that the greatest possible threat to their re-election would come from the equally anti-Clinton primary voters in their districts. Representing more politically competitive states and with longer terms, significant number of Republican senators broke ranks and supported Clinton on the final votes.  

The immediate practical consequence of impeachment is another factor. To remove one president is to install another. Enough moderate Republicans dreaded the prospect of the radical Senate president pro tempore Ben Wade becoming president that they held their noses and stood by Johnson. In Nixon’s case, Vice President Gerald Ford, widely respected for his integrity, was an acceptable alternative among members of both parties. 

Clinton’s case is again less clear. Congressional Democrats would have been happy and Republican legislators unhappy to see Vice President Al GoreAlbert (Al) Arnold GoreTrump's reelection looks more like a long shot than a slam dunk Gore praises Greta Thunberg after meeting: 'Nobody speaks truth to power as she does' Climate 'religion' is fueling Australia's wildfires MORE succeed to the presidency — and for the same reason: it would give him the advantages of incumbency in the 2000 presidential election. But the fervency of both parties’ primary electorates prevented them from acting on this basis. 

Finally, public attitudes toward impeachment play a large role. From 1789 to 1973, only one president, Johnson, underwent the process, and that failed effort seemed to discredit impeachment as a “vengefully political act,” such that in 1960 the political scientist Clinton Rossiter noted, “I do not think we are likely ever again to see such a trial.” Rossiter was proven wrong just fourteen years later.  

From 1974 to 1999, two presidents were in effect impeached. Every president since Clinton has been the object of a grassroots impeachment campaign by opposition party activists. In the contemporary climate of bitter partisan polarization, impeachment strikes many as just another method of “politics by other means.”

Clearly, Trump is unpopular, historically so for a recently-elected president and shedding “strongly support” backing even among Republican voters. It’s also clear that many Republican legislators would be much happier with President Mike PenceMichael (Mike) Richard PenceSioux City newspaper endorses Biden ahead of Iowa caucuses Four endings to the Senate's impeachment trial — and none is good for Democrats Jeffries, Nadler showcase different NY styles in Trump trial MORE instead of President Trump. Even among GOP voters, Pence’s numbers are higher than Trump’s. And public attitudes toward impeachment as a weapon of political combat show no signs of abating.

It comes down to the partisan composition of Congress. The Republican-controlled 115th Congress is unlikely to impeach Trump. But the Democrats may well take control of the House in the 2018 midterm election and — depending on the extent of Trump’s unpopularity — conceivably could buck the odds and win the Senate even though they will be defending 25 seats and the Republicans only nine. Such an outcome would make impeachment by a majority of the Democrat-controlled House likely and perhaps alarm enough Republican senators so that a two-thirds majority for removal could be forged in that chamber. 

Michael Nelson is the Fulmer Professor of Political Science at Rhodes College and a Senior Fellow at the University of Virginia’s Miller Center.

The views expressed by contributors are their own and are not the views of The Hill.