It is fairly well-established that Republicans have succeeded in cobbling together majorities in elections at the local, state and national level by identifying single issues dear to disparate small groups such as gun rights, abortion, taxes etc. and pandering to them. Meanwhile, Democrats have trouble bringing their constituents together even for an issue as basic as voting rights. Experts can surely come up with explanations for this phenomenon. It would be more useful to find a single issue that all Democrats and Independents can unite behind.
Totalitarianism is such an issue. Even before his election Donald Trump made no secret of his disdain for the rule of law. Remember his exhortation of the crowds at his rallies to beat up protesters followed by assurances to finance their legal defense if necessary? This could be considered as over-zealous campaigning. Once elected he quickly shed all pretext and took to openly flouting long-established precedents observed by both parties by refusing to relinquish control of his business before assuming office. When he saw how easily he got away with that he was emboldened to use his office to further his business interests. Still Republicans who knew better stood by silently or made excuses for him or worse - cheered him on. Sensing he had won control of the party he wasted no time consolidating his grip by eliminating the few Republicans who dared to voice opposition - former Sen. Dan Coates, Director of National Intelligence, and Sen. Jeff Flake to name two. Now he was cruising and out of control, showing his true colors. Think of the infamous Helsinki joint press conference with Russian president Putin where he sided with Putin over our own intelligence agencies. Seeing no consequences for his behavior he started expressing admiration for the dictators of the world - North Korea's Kim, China's Xi, Turkey's Erdogan, Hungary's Orban - finally openly wishing we had a system where people sat up and paid attention when the Leader spoke. Ironically, it was his desire for a military parade to celebrate Independence Day that proved to be too much - for the military if not for his party. Now more than a year out of office he continues unabashedly promoting his idea of making America great again with the overt support of Republican voters and politicians and "conservative" media such as Fox, Newsmax and America First. The things he and his supporters are promoting - from control of election outcomes by one party to censorship of textbooks - add up to totalitarianism. He has told us repeatedly who he is and we should take him at his word. If the prospect of dictatorship is not enough to unite right-minded Americans, I don't know what is. As to why Republicans, the self-appointed guardians of freedom, family values and American Greatness, would go along with this, my answer is that they have come to believe this is the only way they can stay in power. If you have a different explanation, I would like to hear it.