The student protests, which are for obvious reasons not representative of the whole population, are themselves numerically a small portion of the faculty and staff at the institutions they're taking place at. Excellent recent examples of this: repeated instances of walkouts or sit/stand protests at commencement ceremonies, where everyone involved is arranged out on a field, almost as if to make these kinds of tallies easy to make (but serious tallies of protests at Columbia, Chicago, and UCLA have also been made). It just doesn't take a lot of people to make a lot of noise.

The "10% undecided" thing is a statistical null result, mirroring the last Democratic reelection campaign (Obama's, against Romney), which didn't include any attempted organized effort to lodge protest votes with "undecided" and still ran up those counts.

Polling --- Pew is a good place to start --- shows Israel below every other "major" issue, even among 18-29 year olds --- except (ironically) student debt. The issue gets less important as you go up in age brackets into cohorts that actually turn out and vote.

The groundswell of support for Palestine in America is, I believe, largely an Internet phenomenon. It's easy to forget that we're the weird people who tune in to this stuff. Most people just live their lives, and, for reasons that are straightforward to understand, care a lot more that a 12 pack of Diet Coke got weirdly expensive than about whatever is happening across the world. We have the same problem marshaling support for Ukraine!