I think investigating it is a good idea which is what the house of representatives has been doing with its impeachment inquiry. However as of now they still haven't found any solid evidence and it seems like they probably won't. If there's evidence I'm totally on board with impeaching Biden but that applies both ways to Trump too. And in the case of Trump there are substantially more wrong things he has done and there's a lot more evidence of those things considering the number of court cases he's dealing with right now. It's like what happened with Hillary all over again, there's evidence of her doing some wrong things which people use to say Trump is a better choice even though he has many more things wrong with him. And much like with Hillary I think all of this investigation stuff is just meant to make him look bad and if Trump wins it will immediately vanish because they know they either don't really have a case against him or that at most they could give him a slap on the wrist. Either way evidence coming out during discovery from both sides would probably end up making Republicans and Trump look worse than Biden. Which is why even when they win like they did against Hillary they never really follow through.