I don't think Reagan and Gingrich are "little success". I'd also point out that it was exclusive Republican-appointed justices who saved the Second Amendment, killed Roe, and killed government-sponsored affirmative action. Those aren't little successes either.
Strawman argument. No where in my post did I say those successes were "little". However, I will point out that what they accomplished while in office has since been frittered away. Also, Republican-appointed justices tend to be hit-or-miss: GHW Bush appointed Clarence Thomas, but he also appointed David Souter. For what it's worth, Donald Trump appointed three of the justices that overturned Roe v. Wade, and yet you don't support his re-election.
Local issues often have little overlap with federal ones, so a coalition that works at the local level might not exist at the federal level.
Another strawman. Nowhere did I suggest a "coalition". I suggested stating a platform and attracting people to it, and then proceeding to use that support to win elections at a local level. Local issues affect people much more than federal ones: for instance, the crime waves currently taking place in major cities are due to locally-elected District Attorneys refusing to prosecute criminals. Also, if you want to change how voters view issues, you need to change how they are educated. Education is largely controlled by locally-elected school boards. Sure, the Dept. of Education holds a lot of sway, but it is the school boards that hire the teachers and administrators, and choose the curriculum to be taught. Ultimately if you want to change how our children are educated, you need to control the school boards.
The math just doesn't make sense to me. If you have three parties, you need at least 1/3 of the total voters to align with you to win. If you're going for only half of one of the two major parties, you only need 25% of total voters. In other words, it's just easier to win by becoming the majority of the GOP than by starting a whole new party that competes against the other two.
You are insisting on looking only at the Federal level, and in the short term. I am advocating for working at the local level, over the long term. Take over the grass-roots (locally) and the Federal will, eventually, fall in line. It might take 20 or even 50 years, but then that's how long it took for us to end up where we now are.