And the Republican Party has never been totally conservative.
There have never been enough "conservatives" to support a separate party.
Until Reagan's time, they split between the two main parties. (or three counting George Wallace)
Since Reagan, the leading conservative has failed to gain the Republican nomination in the primaries where voters made their opinions and choices known.
Several conclusions might be reached, from an honest assessment of results:
1. Conservative ideas are great, but the messengers aren't
2. The ideas themselves are too narrow to sell to get a majority
3. Probably the most often cited, is that voters are too stupid.
Maybe an appeal to God (or a complaint) to make voters smarter.
But back to reality, FDR was elected 4 times, during my parents' and grandparents' lives. So apparently we have had stupid voters going way back.
For the record, when Reagan served as California Governor, and President he took as much or more heat from his political opponents, the media, and even some Republicans, as has been true for the first 1/8th of Trump's first term.
My advice: If you want MORE "conservatism," better sell it better. Reagan did, but none since really has done so.