Pish-Posh.
If you're a politician who can wave a magic wand and make student loan disappear, surely, you can make it so the forgiveness doesn't have to be included as income.
It's possible that Sanders hasn't thought about this little obstacle yet, but it might be fun to bring up with any young millennial if they demand you pay for their loans.
Well, in any case they aren’t getting it past the Senate or POTUS Trump.
WRT mentioning it, the purpose is to reinforce how much of a short-sighted idiot Sanders (and others who propose the same thing) is.