I'm not a big fan of the wage holy war against inflation forget everything else.
I think the most important economic number is quarterly economic growth which is the engine of the whole thing. And that it was the deficit spending of the Reagan administration which pulled us out of recession.
We might have to just agree to disagree. Although I am willing to take a look at some economic statistics. I'd also be interested in what Robert Reich thinks about this.
Neither am I. I think central banks are insanely obsessed with inflation, that the 3% target is garbage, that Print Yen could have saved the Japanese economy in the early 1990s, etc.... But the 1970s were different, which explains why the banks are hyper-careful today even if one disagrees.
Stagflation. If inflation produces economic growth and a drop in unemployment then we be good. If inflation produces nothing but inflation, there are problems: stagflation.
The dove Miller followed your plan, expecting high and growing inflation to produce economic growth and considering 6.7% inflation to be reasonable (which, if it was stable 6-7% instead of rapidly growing, he was close to having a point on), instead growth stalled and inflation increased faster. Stagflation.
Link
Robert Reich said:
A generation ago, they paid too little attention to inflationary forces, so Paul Volcker who was then Fed chairman, had to break the back of inflation and thereby put the economy into a severe recession.
Yes Reagan's Keynesian spending (via the military and tax cuts, basically the worst possible way to do it lol) provided a major boost to the US economy after inflation was brought under control but it was the end of tight Fed money in 1982 that brought about the 1983-4 part of the recovery.
In an ideal world Volcker is Fed chair in 1978 instead of Miller, breaks 9% inflation with 7-8% unemployment for maybe 2/3 as long as 10%+ was IOTL as the Democratic Congress spends tons of money on construction jobs--those were 90% unemployment rate IOTL--such as building trains or what not. The economy would probably have done double what it did OTL in the 1980s, especially if tax cut money was spent on public works.
But we are trying to break conservative Republicans.
Reagan is 100% for two decades and beyond leader of the conservative wing, if you want right-wing Republicans to lose Reagan has to be destroyed. Despite being a New Deal Democrat once upon a time he really isn't going to change his mind post-GE speeches in the 1950s, he simply adapts to what the audience wants. (So, potentially you could have a populist instead of conservative Republican Party and he'd adapt, but that's pretty hard too.)
Reagan was an actor, and not a good one, but bad actor beats good politician. The man had Alzheimer's when he was President and either backed or was so dumb/brilliant to avoid knowing about Iran-Contra and treason. He is not someone whose mind could be altered like you suggest without a POD in the 1950s (wherein we could get Democratic President Reagan

, which is great fun I promise). He ran his speeches on index cards filled with lies, and just shuffled the order for different venues. Honestly the two best things he did were breaking inflation and dealing with the Soviets decently despite his rhetoric. The only way conservative Republicans are weakened once Reagan is President is to make his Presidency horrifically bad. They certainly weren't remotely stopped with Nixon or Ford as President, nor Reagan's defeat to Ford in '76. Nor would Reagan as moderate or whatever do much to slow them. Crazy people just keep going, alas.
Edit: Before Reagan I can think of tons of PODs, once Reagan is in office the options narrow to making Reagan a complete failure, I'm afraid, unless you give him a personality transplant.