Removing Comey as FBI Director caused a huge uproar, and with good reason. Comey was the man leading an investigation into the Trump campaign's potential ties with Russia, and Trump removed him. The reason that Trump originally gave for Comey's firing was his handling of Hillary Clinton's email investigation, which was flimsy to begin with and which he himself has now directly contradicted. If Trump indeed fired Comey because he believed that the FBI investigation was getting too close to the truth on the Trump-Russia scandal, then it would be hard to argue that the move was defensible.

There are still big questions as to whether this could count as full obstruction of justice, which would be an impeachable offense. It was, of course, the sort of obstruction of justice that opened Nixon's impeachment proceedings, instead of any of the other crimes that he committed as president.

If any of the multiple investigations into the Trump campaign's dealings with the Russians lead to the finding that he did, in fact, actively collude with Russia in order to win the 2016 election, then Republicans in Congress would have little choice but to call it treason and impeach him on that count. So far, though, there is only circumstantial evidence of collusion, and Trump himself has repeatedly and vehemently denied all of the allegations.

Everyone learned what the Emoluments Clause of the Constitution was even before Trump's inauguration, just because so many people were saying that his decision not to disassociate himself from his business would put him in violation of it. The clause says that U.S. officials can't accept money from foreign governments, and some have argued that Trump is doing that every time a foreign dignitary chooses to stay at a Trump property. These arguments aren't just coming from the media, though — there's actually at least one lawsuit on the matter. If Trump is found to be in violation of the Constitution in a court of law, then that could be a legitimate reason for impeachment.

So far, there's no evidence of Trump having bribed anyone, Russian or otherwise, but it has become crystal clear that he does not want anyone getting ahold of his tax returns. There are any number of things that he could be hiding there, like mob ties, scant charitable donations, or a low net worth, but bribery through business dealings could certainly show up, and it would definitely be an impeachable offense.

One of Nixon's articles of impeachment was abuse of power, relating to the way he had "repeatedly engaged in conduct violating the constitutional rights of citizens" and misused his own power and the agencies that he had some level of control over. If Congress wanted to, it seems like Trump has done several things that could fall under that umbrella, from using federal funds to investigate unfounded allegations of voter fraud to potentially taping his conversations with Comey, as he implied in a Friday morning tweet.

When it comes down to it, it's Speaker of the House Paul Ryan and Senate Majority Leader Mitch McConnell who would have to get the impeachment procedures going — which they could be forced into, if a strong enough reason comes up. However, it's not inconceivable that the congressional Republican leaders could decide that it would actually be more beneficial for the party to have Mike Pence as their 2020 presidential candidate rather than Trump — and then they could use any of the reasons that they're currently ignoring in order to launch an impeachment and try to get Trump removed.

This is an extremely unlikely case, but I'd say that in 2017, nothing is out of the realm of possibility. Trump is an absolute loose cannon, whereas Pence is a total known quantity. His conservative credentials are as impeccable as they are extreme. Trump's approval ratings are already at near record lows, and should his support from his base start to slip away, then the GOP might like to find a way to replace him instead of risking a huge Democratic victory.

By far the most unlikely way that Trump could be removed from office is not through being found guilty after an impeachment, but through the machinations offered in the 25th Amendment. The purpose of the amendment is to provide a chain of command if the president is rendered incapacitated in some way. The way the president can be removed, then, is that the vice president and at least half the members of the Cabinet must send a letter to Congress stating their belief that the president can no longer carry out his duties, at which point the vice president becomes the acting president.

Many have pointed out how inconceivable it is that Pence and enough of Trump's cabinet members, some of whom were picked largely for their loyalty, would suddenly decide that Trump's tweets are evidence of a terrible mental illness. However, a supermajority in Congress could also theoretically take it upon themselves to evaluate Trump's mental fitness and then remove him if they found he was lacking. Again, though, it is highly unlikely that this would ever take place.

To sum it all up, Trump's impeachment is still a far off dream in the hearts of liberals everywhere — but it might not stay that way. If the world gleaned any lessons from 2016, it's that anything, especially in politics, is possible.