Conservatism after Reagan was just a grift.
Love or hate Reagan, he actually did fight for some of the things he believed in. When the Bushes ascended to power, they saw a rapidly declining voter base and decided, like many GOP sellouts, to cash out while the going was good with the Military Industrial Complex while propping up Reagan's corpse. And while they cashed out, they traded hands with the Democrats until one party rule under them would be established, and then probably join them to milk this country until the last bit of wealth is drained from a dying superpower and then move onto China, which they helped create.
Trump, a man who is essentially a 90's Democrat policy wise and more consistantly socially liberal than any president before him, said "Fight back." The Neocons hated it because the grift was disrupted. The Democrats hated it because their one party rule and grift were disrupted. But the Republican base loved it, because it wasn't just a grift anymore. McCain and Romney were made the biggest examples of this, from becoming GOP frontman and faces of the party, to laughingstocks and reviled.
Trump put it best in the 90's. "The most capable people are not running for office and that is horrible commentary on the country. I see it as someone with my views, which may be right, but a little bit unpopular, may not get elected over someone with no great brain but a big smile."
It was all smiles and empty promises before him, and his entire election was a formal declaration of that by the voter.
While I admire the orientation of your sentiment, the history is not quite true.
The Republican Party has, from its inception, been the party of big business and big money, going all the way back to when an anti-slavery railroad lawyer became its first President. The Democrats were the populist party of farming families and the working man, and had a seemingly unbreakable hold on this identity until some time in the 1930s, when ideological Communists began to infiltrate the party. There were anti-Communists in both parties, of course (Johnson & Kennedy were stridently anti-Communist), but Marxism's sociopathy, anti-patriotism, internationalism, and militant violence ultimately found its home in the Democrats, with the New Left ascending after Johnson declined to run for reelection and in the wake of violent riots.
The ascent of the New Left, with its emphasis on social upheaval, crippling law enforcement, atheism, the Sexual Revolution, and so on, drove the middle class and evangelicals out of the Democratic Party. They did not find a welcoming home in the Republican Party. The GOP continued to be primarily interested in cultivating donors from among the upper class and ensuring they got riders tacked onto whatever bills the Democrats were working on; the party was mostly run by mid-Atlantic bluebloods who found these so-called "conservatives" fleeing the chaos of the Democratic Party to be a noisome and classless bunch of rabble.
The original conservative grifter arose in this milieu, a man by the name of William F Buckley, Jr, who decided that the path forward was whatever got William F Buckley, Jr, invited to the best cocktail parties in DC. This meant, of course, purging the party of populist rabble-rousers. While the Democrats took the strategy of keeping its weirdos out of the media, but still harnessing their energy to win power, under Buckley's influence, the Republicans took to outright purging anyone who threatened their respectability and 6-figure donation checks, beginning with the John Birch Society, moving on to the paleocons, and eventually sweeping out all the immigration skeptics.
Conservatism was
always a grift
. Occasionally, someone who wasn't just there to swindle Republican voters out of their donations popped up, but both GOP itself and auxiliary conservative nonprofits have always focused their efforts on neutralizing people who threaten the grift, whether it was making GHWB Reagan's VP or sending armies of consultants to suck up Tea Party donations and prevent them from being spent on campaigns. The most valuable thing Trump did was expose the scam. If you had your doubts before, when the Republican Party appointed Robert S Mueller based on transparently fake allegations to cripple the Trump presidency, that should have been the last time you trusted these snakes.