My guess: regardless of which party wins the presidency in November, there will be as much accountability for this senator and others like him as there was for the George W. Bush administration officials who lied the country into war and implemented a program of torture. That is to say, none whatsoever.
Fun fact: AOC and Ted Cruz have cosponsored legislation banning Congress folks from lobbying for life. I’m unaware of the current status, but people still work across the aisle and not all hope is lost. We must push on. This (excellent) reporting by ProPublica is part of that.
The calls for the senator to face a grand jury coming from some Congresspeople are encouraging. I'll still be pleasantly surprised if he serves a single day in prison.