Unfortunately it is a matter of voting blue enough, not just blue. In some areas politicians, even Democrats, regularly relate to their constituents by bashing "East cost liberal elites" despite having degrees from Ivy League schools. If Doug Jones had said that a liberal arts education is valuable for developing into a well-rounded citizen his race would have ended then and there.
Even so, this comment is very interesting to me.
I frequently see on Hacker News the sentiment that modern higher education is a bubble. That if we don't actively encourage young people to consider a life in the skilled trades, we should at least be teaching respect for those who do.
But at the same time, it's hard to ignore the open derision toward non-college grads.
I mean, in this particular example, why SHOULD non-college grads support a politician's promises to subsidize colleges, at the expense of other more direct interests? There are obvious cultural/tribal resentments in play, as you're talking about transferring wealth from one class to another class which openly looks down upon the first. But even separating emotion from it, it's hard to criticize strawmen for opposing policy that might well reasonably be seen as voting against their own interests.
George W. Bush famously spoke of following his "gut" when asked about his decision process concerning foreign policy. In doing so science, research and general means of informed decision-making were dismissed as a way for an elitist to tell laborers that they're too stupid to understand his thought process. The hypocrisy is that he himself went to Yale and Harvard and clearly values higher education; he joined the same secret society at Yale to which his father and grand-father had belonged. This trend has continued to the point that lowly insults are preferred by most voters over policy discussion. This is true of both parties. (e.g. "Pocahontas", "motherfucker")
The reality is that education in and of itself is a societal equalizer. A liberal arts education was developed in the ancient world to equip people with the skills that they needed to live freely as members of a society: logical reasoning, self-expression and the ability to record your thoughts and interpret the thoughts of others. We now speak of education in terms of time commitment and expected pay-off, the massive debt considered an unavoidable nuisance. It is often after a child has selected a college or university that they consider how they will pay (or accrue debt) for it. The elites know that education is a equalizer and that is why they try so hard to frame it as a tool for the enemy of the common people. The last thing that the elites would want is commoners getting wise. When common people do see the value of education they are buried in debt to stifle their upward mobility.
To answer your question, non-college graduates should support the subsidization of higher education because nothing could do more to serve them and their interests. For the time being tough, pursuing an education may mean separating the concept of education from what we have learned to think of as an educational institution. I don't have a college degree and I don't want one (i.e. I don't want to earn one at this time) but I am convinced by the reasoning behind supporting education that has been repeated for thousands of years. In my opinion it is tantamount to supporting the advancement of human civilization and right now we desperately need a renaissance.