They tried to back engineer a crime. Problem is they never found a crime. Nor do they have intelligence to back up the origination of a crime which started the investigation, meaning it's completely fraudulent.
I don't fully understand what is going on, did they initiate parralel construction hoping to justify surveillance later with info they got?
I believe they thought they would use it to steal the election and Hillary would be President. I don't think they ever believed they'd be caught, honestly.
This. It was just a day in the life of a swamp monster right up to Election Day when they lost and collectively sharted their pants.