The Civil War had just concluded and Reconstruction had already begun.

But Johnson, the racist that he was, opposed many aspects of Reconstruction. As the Senate website points out: “Johnson vetoed legislation that Congress passed to protect the rights of those who had been freed from slavery. This clash culminated in the House of Representatives voting, on Feb. 24, 1868, to impeach the president.” Both the House and Senate were controlled by Republicans.

But here is the hurdle that the founders built into the process to make it nearly impossible to remove a president: While it only takes a majority of the House to impeach a president, two-thirds of the Senate must vote to convict in order to remove the president.

In the Senate, the three articles of impeachment that were voted on all fell short by one vote, and that is because seven Republicans switched sides and voted with the Democrats for acquittal.

One of those Republicans, Senator James Grimes of Iowa, explained his actions this way: “I cannot agree to destroy the harmonious working of the Constitution for the sake of getting rid of an Unacceptable President.”

Even a Supreme Court associate justice, David Davis, a Republican who had served as Lincoln’s campaign manager, reportedly opposed Johnson’s impeachment, even though he believed him to have “qualities totally unfitting him to be the ruler of a people in the fix we are in” and calling him “obstinate, self-willed, combative, slow to act” and in possession of “no executive ability.”

Johnson was impeached before the advent of modern polling, but that polling did exist when Nixon resigned and Clinton was impeached.

It is important to note in Nixon’s case that the televised Senate Watergate hearings had started and the Saturday Night Massacre occurred in 1973 and yet the percentage of people saying he should be removed from office never rose above the 30s that year, according to Gallup. It wasn’t until after the House Judiciary Committee recommended impeachment that a majority of Americans thought he should be removed.