There was nothing historic about the Senate acquitting President Donald J. Trump on February 5, 2020. Rather, the Senate impeachment vote was simply another day of two political parties demonstrating how the contemporary ideological divide within Congress has crippled the checks and balances of the United States federal government.

Simply put, the process of having a bill become law requires tremendous time and energy, among other things, but it most importantly requires a majority. No bill in either legislative chamber can become law without a majority vote, and therefore, the party in the majority inherently has an advantage with regard to which bills will be heard by the House of Representatives and the Senate.

Since the mid-1970s, the partisan polarization in the United States Congress has steadily increased. This has resulted in a reduction of bipartisanship and an increase in partisan antipathy between the two majority parties in the United States. As a result, most actions by Congress are the result of party-line voting in which members of Congress from one party will generally vote for bills that the majority of that party is in favor of. To this extent, the party in the majority will hereby have a distinct advantage to further bills they favor and prevent bills they do not. As such, the party that controls a chamber of Congress can determine the action of that legislative chamber in such a way that it favors their party’s agenda.

In order to impeach a president in the House, a simple majority vote of over 50 percent is required. Similarly, to convict a sitting president and remove them from office in the Senate, it requires a supermajority of a two-thirds vote. Since, however, a majority is needed at every step to impeach, it is therefore expected that if a chamber is pursuing impeachment against the president, it is most likely that the majority party is the opposition of the president’s party. In this way, the impeachment process for presidents, like a vast majority of the decisions in Congress, is now made along partisan lines.

An example of party-line voting is evident in the impeachment results for President Trump. In the House of Representatives, controlled by a Democratic majority, the vote to impeach the sitting president was almost entirely divided along partisan lines, with all but 5 of the 233 House Democrats voting to impeach President Trump, while all of the House Republicans voted against  impeachment. 

A parallel story occurred during the Senate impeachment of President Trump, where the Republican-controlled chamber voted almost entirely along party lines to not impeach the president, with the sole exception being Mitt Romney, who joined the Senate Democrats in voting to remove the president from office (on only one impeachment article).

The consequence of members of Congress voting along party lines, according to Erik Engstrom, a Professor and the Chair of the Department of Political Science at the University of California, Davis, is that “The outcome [i]s entirely predictable, I think. It’s hard to imagine a world in which you get 20 Republicans [in the Senate] to vote to remove the president of their own party.”

Moreover, not only does the majority party control the votes on whether or not to impeach the president, but they also can determine what evidence will be presented during the trial. This is because to allow additional evidence to be heard during an impeachment trial, the Senate requires a majority of 51 votes. To this extent, if the majority does not seek to hear any new evidence, there is nothing the minority party can do to oppose the majority party’s decision.

With this in mind, this rejection of new evidence occurred during the impeachment of President Trump. In this case, the Republicans holding a majority in the Senate prevented additional witnesses and documents from being considered during the impeachment trial.

Thus, the decision of whether any president now or in the future will be investigated thoroughly for their accused impeachable offenses will be boiled down to whether or not their political party controls one or both chambers of Congress. This is because the impeachment process for presidents has become a political contest over who has the votes to ‘win,’ as opposed to what is necessarily the best course of action to properly conduct a fair and impartial trial.

Significantly, an impeachment process is not a court of law, and as such, an impeachment trial does not need to follow the same rules and procedures as a criminal court. Therefore, even if there were rules to demand that all relevant evidence be brought to trial, “there is no one to enforce that in Congress,” Professor Engstrom said. “Who’s gonna enforce that? The politicians themselves, right; so, it just becomes a political endeavor.”

Hence, the lack of any enforcement mechanisms, in essence, permits the majority party to control the entire impeachment process. As such, there is no method of accountability to require these politicians to uphold the ideals of a fair and impartial trial. Therefore, despite members of Congress being labeled “impartial jurors,” they are yet authorized to disregard potentially valuable evidence so long as their party is in the majority in the chamber.

Altogether, due to the partisan allegiances which dominate every action in Congress, the impeachment process for Presidents of the United States has become an ineffective and biased political endeavor that lacks meaning beyond which party controls the House of Representatives and/or the Senate. As a result, no matter the impeachable offenses the president may or may not be guilty of, it is now a party contest in Congress to determine if one of the most important checks and balances in the U.S. Constitution is conducted at all in contemporary American politics.