Why isn’t the Biden justice department and the FEC pursuing Trump for breaking election law after he paid off Stormy Daniels?

They have so much left from the previous administration to wade through, Its just not that easy to pursue 6 or 7 things all at once.. 

It isn’t illegal if Trump actually paid Stormy out of his own pocket. Non disclosure agreements are not illegal even if they might be immoral. And an individual can spend an unlimited amount of their own money on their campaign.

The issue is that Trumps lawyer Cohen paid off Stormy. That would be an illegal campaign contribution to Trump. But that’s on Cohen.

The other issue with campaign finance laws is that unlike other laws where ignorance isn’t a defense, you have to be aware that something is illegal in order to be prosecuted for campaign finance violations. They would have to prove Trump knew something was illegal and still insisted it be done.