The main weakness of German progressive parties today is precisely that there is currently one conservative party invariably polling 35-40% at the federal level, while three progressive parties (social democrat, democratic socialist, and Green) distribute another 40-45% among them (neoliberals and the nationalist reactionaries get the rest). The democratic left has quite strong popular support, and yet conservatives are better-positioned -- in fact, all but assured of retaining the chancellorship in 2021. What gives?
In this situation, the German system of >50% majorities by coalition won't allow for a "united front" of progressive parties at the federal level -- whereas the conservative party can simply choose the progressive party (or neolibs, when those are willing) that makes the most palatable concessions to them, and thus seal >50% of the seats.
Currently, for the first time in the Second Republic, the SPD seems to be a second-tier party when it had previously shared the first tier with the conservatives. I'd written about possible reasons why its electoral support was eroded (and largely went to other left-wing parties) -- which was presumably this lack of perceived authenticity over the last twenty years that also weakens the US Democrats now, and social policies that still only favoured the relatively wealthy.
By the numbers, though, the SPD's losses mirror the case of the neolibs (FDP), a party that dropped from ~15% of total votes to below 5% over the course of its most recent coalition years with the conservatives, i.e. 2009-2013. So indeed, are "progressive" politics the issue with voters flipping from the minority faction, or "establishment fatigue" caused by them failing to enact their promised policies against the majority faction, whereas conservative voters obviously care much less about anti-establishment policy? Seems like the latter to me.
From all I've seen (which may well not have been enough),
the prevailing narrative among "conscious" Rep voters appears to be that "socialist" agitation (however they define it) is trying to gain influence with the establishment, who encourage this because they see socialist doctrine or policies simply as an effective tool to ensure D-voting cities eclipsing the votes of the bloomin' countryside and turn the state Blue forevermore; once done, they'll happily throw the relatively powerless socialists, now an unambiguous threat to their goals, under the bus again, and can even pretend to be social democrats.
Compare the above to how some "conscious" Dems generally either believe that socialism
will indeed only play handmaiden to the establishment and get crushed once no longer useful, unless socialism manages to devalue if not dismantle democracy altogether (Myzozoa's position, as I understand it), or posit capitalism or white supremacy (however they define it) as the pernicious handmaiden to the establishment instead.
So my guess is -- these 2020 Dem-to-Rep flips occur in part because Biden is perceived as same-old in a way that Sanders would not be, yeah, but that's only one part of it. In addition, the 2020 flippers now believe to have realized, after 4 years of Trump, that socialism is the most powerful ideology "in bed with the US establishment", didn't think so in 2016, and probably aren't the kind of right-wingers who want the fascist white ethnostate now etc.
"Hot take", maybe? I don't think anyone here would be fazed if I'd said voters flipped Rep-to-Dem 2020 because they believe to have realized, after 4 years of Trump, that capitalism or white supremacy is the most powerful ideology "in bed with the US establishment", didn't think so in 2016, and probably aren't the kind of left-wingers who praise Stalin etc.
It doesn't matter whether reality reflects or refutes such a motive, it matters that
they think it's well-founded. If voters flip Dem-to-Rep, they might well have consciously lost faith in the threat of capitalism / white supremacy, but think the threat of socialism is very real -- and further appeals to this may only cause them to double down on their flip. So try a different approach if you want them to flip back. I think that those "conscious" Trump voters genuinely believe they are voting for the
real social democracy while the D voters are mindlessly falling for "gov't-approved socialism" meant to keep them on a leash. Convince them that it is not so, because the thought is not as inherently stupid as you might think. An example:
Why has Germany run a state-subsidized system of universal healthcare since 1883? Because Bismarck assumed that implementing one would deprive the nascent and still relatively radical SPD (or its predecessors) of one of its most popular platforms -- and thus make increased repression against socialists more "palatable" to the German working class. He was wrong, though -- his rationale was seen right through, the implementation not materially appeasing enough, and the "holistic" appeal of yet-untried social democracy in 19th-century Germany far underestimated.
One more thing about the question "who would consciously vote for white supremacy?" ("whites lol", yeah, but which ones). I've often heard that Hitler flipped the economically destitute and "revanchist" lower-middle class away from both left- and right-wing parties, while covertly appeasing executives and bankers until the reactionary oligarchy, reigning at the time via (constitutional, but abused) state-of-emergency dictatorial powers, felt pressured in several ways to appoint his popular platform to a "legitimate" government -- which promptly deposed them "legitimately" within two months (the Nazis loved their lie of the "legal revolution").
That was also the contemporary commenters' explanation for the origin Hitler's electorate, but it's not so clear under scrutiny.
That study points out, again, that this assumption is as overwhelmingly true in the case of rural Protestants as overwhelmingly false in the case of rural Catholics, while urbanites of
both confessions were less polarized. The obvious question is why the Catholics resisted Hitler so much more than Protestants, because it was clearly not due to any shared Christian tenet between them, nor progressive politics, and I think the answer lies with Bismarck's politics (again) in his trying to build up Protestants as a tool for German (read: Prussian) nationalism against Catholics, who supposedly felt much closer "anti-nationalist" ties to the Holy See, or felt nostalgic nationalism for the recently-ended sovereignty of the South German states, which had not acquiesced to Prussian dominance as readily as much of the North.