I tend to put most of what President Trump has done into two general categories.

The first category is things that a normal Republican president would do under normal circumstances. This includes promising to work with Congress to repeal or modify Obamacare, reinstating the international abortion funding ban, and appointing a well-qualified conservative judge like Neil Gorsuch to the Supreme Court.

The second category is things that a normal Republican president would not do that threaten to weaken or undermine our traditional liberal democratic norms and institutions in our political system. This has been well-documented since before Trump’s election (see here, here, here, and here, for starters). No normal Republican president would decline to commit to accepting the outcome of election results before the votes are cast, engage in a high-profile campaign to delegitimize our media institutions, threaten to jail his or her campaign opponent if elected, bar reputable organizations like the New York Times and CNN from a recent press gaggle, publicly call the legitimacy of the judiciary into question, repeatedly assert that millions of illegal votes were cast in an American presidential election, sign an executive order based on “Muslim ban” rhetoric during a campaign, appoint a proud white nationalist as Chief Strategist to the U.S. president, invite a foreign government to commit cyber-terrorism against the United States, etc.

The thread connecting everything in the second category is that they show a lack of respect for the basic political norms and institutions that are vital for maintaining a liberal democratic form of government. These include guarantees on the freedom of press, speech, and religion as well as respecting the legitimacy of the process and outcome of elections. They also include a basic commitment to societal pluralism. These are things that, despite their differences, Democrats and Republicans usually are in full agreement on.

Theoretically, Congress and the Judiciary should be able to serve as a strong check on the Executive to defend these basic underlying democratic norms and institutions. While the Courts have been able to serve as a check in some cases so far, Congress has both the opportunity and responsibility to take the lead. Given that Congress is currently under Republican control, GOP leaders will decide how much of a check they desire to be. Congressional Republicans are therefore currently faced with a difficult choice: work with President Trump to accomplish their policy goals or oppose President Trump’s attempts to undermine the foundations of our democratic system of government. So far they have largely prioritized the former and declined to do the latter (with some notable exception like John McCain, Ben Sasse, and Darryl Issa).

Why might this be? My strong hunch is that Congressional Republicans have so far declined to oppose President Trump’s anti-democratic gestures because their constituents do not want them to do so, or at least are happy with them not making it a priority.

Take Exhibit A: right now rank-and-file Republicans in the public largely approve of the job that President Trump is doing. Congressional Republicans, knowing this information, have little incentive to oppose the president as they fear a primary challenge in 2018. Take also Exhibit B: according to an October 2016 survey, less than half of Republicans in the U.S. do not believe that accepting the outcome of election results or defending First Amendment freedoms of speech and press is very important to a strong democracy. Again, Congressional Republicans thus have little incentive to prioritize these things if their constituents don’t either.

My great fear is that we are quickly approaching a situation where our two major political parties are not only distinguished by whether they are ideologically liberal or conservative but also by whether they actively support and defend basic liberal democratic norms and institutions or not. In the past, both the Republican and Democratic parties have been honorable defenders of American democratic norms and institutions. It is difficult to say, though, that the Republican Party as a whole is strongly committed to defending liberal democratic values right now.

This is a scary place to be. As someone who has voted for both Democratic and Republican candidates in my life, as a political scientist to studies what makes democracies strong, as a citizen who believes in the American experiment of individual freedom, limited government, and self-rule, and as a father who wants his daughters to grow up in a land of freedom and opportunity, I implore my Republican representatives in Congress and my Republican friends everywhere, to stand up to President Trump on this.

The ball is in your court, Republican friends. The future strength of our liberal democratic institutions is very literally dependent on the choices you are making right now. I am not prone to alarmism or hyperbole, but I do not hesitate to say that each day you take a pass on loudly making a public statement condemning President Trump’s latest anti-democratic rhetoric (while making clear you are happy and eager to work with him on things like taxes, healthcare, etc.) you become tacitly complicit in the weakening of our democratic institutions. This goes for Republican voters in the public as well: Republican members of Congress will do what you tell them to. Call them up and say “I’m with you on taxes, abortion, gun rights, and healthcare, but I will vote against you if you do not push back right now when President Trump tries to delegitimize the media or the judiciary or claims millions of illegal votes or does nothing to investigate Russia’s attempted subversion of our elections.” They’ll do that if you tell them to, because they want keep their jobs and as Republican voters, you control their fate.

The Republican Party has historically been a noble and honorable defender of liberal democratic values, but they’re in immediate danger of going down in the history books as the party that let Donald Trump weaken our democracy and turn us into a hybrid democratic regime.

It’s time to make the Republican Party great again.