Biden’s legal authority to extinguish student debt, by all accounts, is open to question, so you can be sure the question will be asked. Under normal circumstances, the judicial system would hold that the issue is not subject to challenge because nobody has a sufficient interest to establish standing. The current Supreme Court has shown on multiple occasions, however, that it has no regard for such niceties. You have to assume that Alito, Thomas, and the rest of the reactionary crew are just dying to deliver another stinging defeat to the administration. If that happens, what’s next? Will the disappointed debtors take it out on Biden or the GOP?
It will be the fault of the vast right-wing conspiracy, but my guess is that they will blame Biden. Fortunately, it will be after the midterms.