The Republican and Democratic parties have a similar problem with the tension between maximizing long- and short-term prospects for success. Long-term strategy and planning are difficult, if not impossible, in political parties unless they happen to be the beneficiaries of a one-party system (as in China). Competitive parties are always forced to subsume the long-term to the short, given the logical reality that if they don't hold power in the short-term any strategies intended to play out over time will be difficult to implement. Beyond that, parties are composed of political actors with ambition, few (if any) of whom are going to sacrifice their own short-term interests for something that might benefit someone else down the line.
In the GOP, as I've written about many times in the past, some people seem to realize that the party base of older, white, and largely rural voters is rapidly shrinking in comparison to more diverse and urbanized America. They are forever coming up with some new strategy to broaden the party's appeal, the kind of thing that 20 years ago would have been called "minority outreach" without causing widespread cringing. The problem, of course, is that the party's best short-term strategy for maximizing its success is to double down on white nationalism, something they've done with increasing regularity since 1980. Each election cycle someone in the Party says "Ok this time let's try to appeal to Hispanics, it's important!" and then when it doesn't work immediately, and when they sense that it's not going to gain them anywhere near as many votes as the usual dog-whistle (or plain old whistle) stuff, they go back to what they know.
The Democrats have a similar, although fundamentally less loathsome, dilemma. For years they have known that they need to increase their appeal among what used to be their core constituency, pre-1990: what we generically call "The Working Class." As Republicans rely increasingly on elderly white conservatives, the Democrats have become heavily reliant on highly-educated, largely white professionals. The Democratic base also includes African-Americans, Latinx, LGBTQ+, the young, and other important demographic groups, but the more policy preferences are bent to the desires of better-off middle-or-upper class Democrats, the less appeal it has to those other groups. So the Democrats too find themselves torn in a way this nomination process has demonstrated quite well: try harder to appeal to younger, more diverse, economically distressed people who constitute a huge pool of potential voters who don't tend to show up and vote, or simply max out on the people you can be confident will vote (and, not incidentally, write contribution checks, which are also important)?
Super Tuesday and the reaction to it underscored some of that tension. There were loud cries even on Tuesday evening that the increase in youth turnout Sanders predicted he would produce did not materialize – in short, evidence that while everyone theoretically understands the need to appeal to those voters for long-term success, in the short term the only logical strategy is to give people over 55 what they want: a Biden campaign promising not to change anything too much and to get things back the way they like.
It's not illogical, it's just counterproductive in the long term. Every time the GOP doubles back to "Let's be really racist" it makes even harder the task of, uh, broadening its appeal with people of color in the future. Similarly, every redouble to "This system works well, it just needs some tweaks and better people in charge" alienates more younger voters who very much do not believe that. You can argue, correctly, that "They're not voting now, they're not going to help us win, we can't afford to direct our efforts at them." Any electoral strategy based on young people showing up to vote is risky, to put it mildly. But at the same time, it's hard to shake the depressing realization that each election, each legislative session, each major battle in which the Democrats default to "Look, this is what our loudest and most committed supporters want" makes expanding that base in the future a little bit harder.