I’m not the person you replied to but I can comment to this effect. (Sorry for the wall of text - a lot of context to give about the American two-party system).

America has always found itself entrenched in a two party system. Periods that resemble now (very tight competition between the two parties) are very common in American history, but you do get occasional periods where a single party will be dominant for a long stretch. This says just as much about the unsuccessful party as it does the successful one: one is able to represent a large segment of American society, and the other is not. In this situation, the unsuccessful party will always rebrand to increase it’s relevancy (the alternative is that a party collapses and a new one forms, but that has not happened for >170 years). As an example, the Democratic Party (today includes Obama and Biden) once was the first choice for racist Southerners who were butthurt about the civil war. The Republican Party (today includes Trump) was led by the likes of Lincoln and was extremely progressive in racial issues for the time.

All this to say that the Republican Party doesn’t have to change in name or branding or even leadership to eliminate Trumpism and provide a platform for moderates. History tells us that, instead of a successful 3rd party rising up and replacing the Republicans, we will simply see a relatively short period (maybe 12-20 years) of Democrat victories and then the Republicans will be forced to adopt a more reasonable platform.

To an extent, this is already happening. In 2016, Republican Party leaders planned to adopt a platform that was more progressive on racial and women’s issues - they saw it as a lesson learned from their failures in the Obama era. Those same officials were blindsided by Trump’s popularity and had to pivot the opposite direction to meet the mood of the country. Despite Trump’s success though, his platform was never designed or planned as a long term strategy for winning elections and gaining support. Trump’s supporters are overwhelmingly old compared with his opponents, and thus are literally being replaced.

This should illustrate the extent of the republican party’s failure to adapt: they have won ONE presidential election popular vote since 1992. One. Out of eight that have occurred.

People like OP are an important part of this natural process of party realignment. OP rightly should be represented by a major party, but the modern Republican Party is failing to represent him. His is not a rare opinion in American political discourse; there are millions of people who would vote for more moderate conservatives if they had the option. One impact of this is that more far people are registering as “independent” voters than in previous years.

The end result of this, of course, is that the Republican Party is likely to change to represent people like OP over time. If people like OP begin to feel disillusioned with the Republican Party and it’s platform to the extent that they don’t vote, this process will only speed up. OP can do nothing better to quench the rise of far right trumpism than to be a political orphan for a while. That’s exactly what we’re encouraging by pointing out that his party hates him.

TL;DR

This dichotomy is not new in American politics and OP will actually do more to change the GOP from the outside than from the inside.