Why do 70 million Americans — and many members of Congress — still follow Trump?

The persistent Trump "base" and the Republican members of Congress who maintain fealty to Donald Trump do so for a variety of reasons. They are not a monolithic body but a loosely associated conglomeration of supporters with their own individual or group reasons for remaining loyal to the twice-impeached ex-President.

"Membership" in the Trump base may include entry into one or more of the following categories.

1. "All-in" isolationists, ultra-nationalists, white supremacists, racists and insurrectionists Arguably all those who marched in Charlottesville in summer 2017 and many of those stormed the U.S. Capitol on Jan. 6 are openly racist, and have felt liberated by the rhetoric and policies of the Trump era. For them, Trumpism represented an enticing outlet for perceived slights or a platform upon which to boost their identity, sense of meaning or being, and self-importance. 
2. Opportunists and political chameleons Those who fall into this category recognized that the Trump train presented itself as a vehicle by which one could achieve fame, success, ambition and political or personal gain. Those with political ambition watched Trump's tactics, saw its success and made the decision to be a Trump sycophant and copycat. Matt Gaetz and Marjorie Taylor Greene, mediocre members of society who had the financial means to run for Congress, are noted Trump exampled who will ride this train until it throws them off (and even then will continue to chase it). Fox News talking heads fall into this category as well. Following opportunity often requires suppressing any logic, rational thought or independent notions. This is a key factor behind the flip-flopping of politicians like House Minority Leader Kevin McCarthy (who has vacillated in his defense and indictment of Trump and his insurrection), Ted Cruz and Marco Rubio (two former Republican rivals to Trump who were mercilessly dragged by him only to become full-throated supporters), and Senate Minority Leader Mitch McConnell, for whom every Trump-related decision comes with an eye on the next election cycle. These are the political chameleons who will change as needed to survive. 
3. Narrow-minded, limited information input and vulnerable to cultism This group of followers is either actively or passively limited in the information that they receive through on-air and online media outlets. As a result of their "soda straw" approach to Republicanism, conservatism or Trumpism, they are simply not exposed to the damning evidence that exists to show Trump and the GOP's unethical, immoral and likely criminal behavior. This is the consumer of a steady diet of right-wing sources such as Fox News, OANN and Newsmax. One cannot discuss this group without referring to the concept of shared omnipotence, a cult leader tactic by which followers are repeatedly told that the leader will take them to a "promised land" (e.g., a place of increased wealth, no immigrants or people of color, world superiority or dominance, protection from death) and if they don't follow, the result is certain doom. 
4. Voting with their pocketbook Members of this group are totally focused on individual and family wealth. They voted for Trump twice because of his tax breaks for wealthier Americans. They may be repulsed by Trump the man, but they feel compelled to vote for him because they are profiting from his policies. They are one-issue voters and they will not be deterred by any of Trump's antics, lies or dishonesty.
5. Hold your nose and vote Republican These group members are cousins of the previous group. This faction is diehard conservative Republicans who are unwavering in their support of the GOP based on years of support and the hope that this period is an aberration that will correct itself soon. Sen. Mitt Romney is one of the remaining stalwarts of this group. 
6. But he and I are Christians! In many ways an outgrowth of the latter group, these followers maintain their identity and faith as evangelical Christians. They have consistently voted Republican for a widely varying set of reasons, the abortion issue first and foremost among them. Now, electing and supporting Donald Trump, who is arguably the embodiment of sin, requires resolution of a huge case of cognitive dissonance. To accept Trump and Trumpism requires that a "true" Christian must fit this obviously square block into a circular halo. Attempts to reconcile this dissonance include pairing Trump with known Christian leaders and evangelicals, citing scripture that appears to validate this choice, or projecting Christian values on to Trump and Trumpists.  

Not all Trump supporters are alike. It is inaccurate and wrong to lump them together. It misses the point and undermines any chance for reaching out to supporters in order to reinvent a Republican Party that is reasonable, more moderate and hinged to our American democracy.

Short of convicting and repudiating Trump at his upcoming impeachment trial — which appears highly unlikely — we will be left with the task of disambiguating and understanding his followers and what motivates them, and connecting with as many of them as possible. The future of our two-party democracy, and our entire country, will hang in the balance.