Student debt was not a campaign platform he ran on, it was something he did during his presidency.
He did run on Green New Deal and the original proposal that later became the $2 trillion Infrastructure investment/bill/plan.
But to your point, yes he ran on platforms that people got excited. Both of those platforms were new economic opportunities for people in a time when people when much of the labor class was jobless from COVID.
Depends on what kind of programmer.
If you’re doing data engineering/science (more of an adjacent field), you need to know linear and probability pretty well to build models, or have data harvested in ways that can be put into vectors.
If you’re doing relational DB stuff (like SQL) set theory helps a lot.
Basic boolean operations in general is also good to know. You don’t need to go too deep in the weeds of boolean math unless you’re also doing a lot of hardware-level stuff.
Any field you go into (not just programming), I would say just basic math for regular financial competency is good to know. Also to analyze your budgeting, your costs, time spent, effort needed, etc.