I don’t know if I can help, but I’ll try. Each party has its base. Those who identify themselves as Republicans and or Democrats, those who affiliate with the two major parties. History has shown on average 92% of those who identify with a political party will vote for their party’s candidates. I suppose you could call those who identify with the GOP as Trump’s base. Usually a losing presidential candidate or a president who has served two terms silently fades away like Obama, Bush II, Bill Clinton, Bush I, Reagan, Carter etc. Up and until Trump, none has tried to continue as leader of the party. Trump in doing so is unique, the only one I can think of.
I would say you’re correct in that prior to Trump it was an ideal, a philosophy that the Republicans believed in. Not the man, which again makes Trump unique. I think the Republicans, Trump’s followers have thrown a lot of the conservative philosophy out the window. They’re not interested in ideology anymore, just the man.
As for Republican elected officials, if they want to keep their jobs, they must to toe the Trump line. If they don’t, they’ll be primaried out. Regardless of party, self-preservation is the top priority of any elected official. The fact that these Republican elected officials seem to bow to Trump, whether they believe in Trump or not or what he has to say, it’s self-preservation to the max.
Yes, the Democratic Party has its base also. But unlike the Republicans, today it is based more on political philosophy then on any one person. Like any large group, the Democratic Party has its factions. Usually they have kept the in-fighting behind closed doors. Probably due to their narrow margins in both the house and senate when they want to pass any legislation, the Democrats must get 100% of all their elected members to vote for whatever it is they want to pass. In the past, that was far from necessary. Even with the ACA in 2010, the Democrats had 256 representatives, they could afford to let 34 Democrats vote against it and still pass the ACA. 34 did vote against the ACA with little to no fanfare. No out in the open in-fighting.
I’ll have to disagree that the Republicans have proven they can beat the Democrats regularly. Since FDR, the two major parties have swapped the presidency every 4 or 8 years. Bush I was the only candidate to win back to back presidencies for his party, Reagan to Bush I. Beginning with FDR, the Democrats controlled the House for 58 out of 62 years to include 40 straight years, ending in 1994. Since then even the house has gone back and forth. Now the big tent Democratic Party from FDR through let’s say Reagan was a completely different party from todays. Then the Democratic Party was known as the working man’s party, the Republican Party, the party of business or what was referred to as the country club party.
Few today refer to the Democratic Party as the working man’s party. It’s more of a social justice party. The working man has slowly been moving to the GOP. It’s the Democratic Party that has suffered the biggest drop. From averaging around 45% of the electorate from FDR to Reagan, then 35% from Bush I to Obama, now down to 30% and below. Whereas the Republican party has basically maintained around 28% of the electorate from FDR to present. The GOP has been as high as 32% during Eisenhower and again during Reagan and as low as 21% of the electorate during the last days of Nixon, then Ford and Carter. It took Reagan to revive the GOP. The Democratic Party hit 51% of the electorate in 1961 and again in 1964. According to Gallup, as of 19 Oct 2021 26% of the electorate are Republicans, 26% Democrats and 44% independents. This is a historical low for the Democratic Party going back to FDR. It's also the first time since FDR that the two major parties have been even. From FDR until now, the Democratic Party was always the larger of the two major parties.
https://www.pewresearch.org/politics/interactives/party-id-trend/Like you jgw, I’m not sure whether I explain anything or went off on a tangent. Like you also, I’ll let it be and see what comes of it.