It's quite common for politicians to return money that is stolen/foreign/otherwise when they find out.
Sometimes because the law requires it, but also if they don't, the attack ad for their opponent writes itself.
Although obviously it depends on how much time has passed and whether the money should already be considered "spent". Because even if the politician wants to repay it, new donors want their money going to re-election activities, not going to repay FTX. After a period of time, you might as well be asking the television stations to return the money they received for running the campaign ads, which... isn't gonna happen.
Sometimes because the law requires it, but also if they don't, the attack ad for their opponent writes itself.
Although obviously it depends on how much time has passed and whether the money should already be considered "spent". Because even if the politician wants to repay it, new donors want their money going to re-election activities, not going to repay FTX. After a period of time, you might as well be asking the television stations to return the money they received for running the campaign ads, which... isn't gonna happen.