Impeachment is a strong word.

In the course of American history only two presidents have been impeached: Andrew Johnson and Bill Clinton. Proceedings have been made in some form or another against any number of other men who've held the Oval Office, especially including Richard Nixon who eventually resigned as a part of an impeachment threat levied as a result of the Watergate scandal.

There is the possibility that that short list may soon grow by one.

Following testimony by special counsel Robert Mueller about his investigation into Russian interference in the 2016 election and President Trump's alleged obstruction of justice in firing FBI Director James Comey, a number of House Democrats are more intent than ever to begin impeachment proceedings against the president.

The number of Democrats in the House of Representatives who've come out officially in support of impeachment now numbers 109, nearly half of the 235 Democrats in the House.

Officially, that number doesn't mean much. In order to an impeach a president (or any federal executive for that matter) you obviously need a majority in the House. And 109 (110 if you count Republican-turned-Independent Justin Amash) is far from a majority of 435.

Logistically, however, 109 might make all the difference in the world.

Namely, it's an issue of optics. Unity amongst the Democratic base about this issue is strong, and as that strength among the constituency continues to build, Democratic lawmakers will have a harder and harder time explaining to them why they are not beginning impeachment proceedings against President Trump.

This heat might most effectively be felt Democrats who live in heavily blue districts that have not yet come over to the pro-impeachment camp, chief among them House Speaker Nancy Pelosi. In fact, Pelosi is the Democrat who represents the district that most definitively voted for Clinton in 2016 (by a +73 margin) but has not yet plunged toward impeachment.

For Pelosi this makes some sense: her okay on impeachment would mean that a vote would surely happen, putting certain lawmakers (chiefly Democrats who won in swing districts in 2018) in an awkward position. As many pundits have noted, while the call for Trump's impeachment has been most fervent amongst the far-left, far-left House districts were not the ones that carried the day in 2018. That honor, rather, goes to many swing suburban districts that Trump won or lost by relatively little in 2018.

Aside from Pelosi's reticence on declaring impeachment, many other Democrats may be wavering on issues of practicality and achievability. After all, the 2020 election is only 15 months away and many Democrats have a strong notion that instead of expending political firepower removing Trump via impeachment, he might be removed through the vote. Additionally, it seems in all likelihood that Senate Republicans would not vote to remove Trump, as the House vote on impeachment essentially only begins a trial based on high crimes and misdemeanors with the Senate body presiding as jury.

What's more, the issue of impeachment is mostly unpopular with the American people. The idea gains only 34% of support among independents and a mere 6% of support among Republicans.

While it may not be that the House of Representatives reaches a consensus on whether or not to hold an impeachment vote before the 2020 election, there is no denying that the continued strain over whether or not to do so will continue to pull at the divide between the progressive and moderate wings of the Democratic party.

Impeachment is a strong word, and wielding it ushers in strong consequences.