In this case it is one of non-government timing. The whole Somali fraud, welfare fraud, Medicare fraud, etc., was brought the public's attention by people like Nick Shirley who put it on front street. The Democrats running the states where this was going on rampantly were doing nothing about it. Trump and his administration stepped in and started charging the fraudsters. The Democrats, not wanting to look stupider than they already do, jumped on the bandwagon to at least make a visible attempt to do something about the worst of it.
Think about that. In California, the Democrat response to open fraud there was to pass a bill making it illegal for people like Nick Shirley to do independent investigation of it! How more blatant can the Democrats be than passing a bill to make fraud, which apparently is highly beneficial to them politically, impossible to detect and investigate?
That's why it is happening now. This didn't start last month. It started last year and gained momentum. Now it's an election year issue as well.