Whilst you are in paralysis waiting for the Conservative Treehouse to provide it's next sermon from the mount here is a wiki (pedia not leak) explaining how FISA works.
https://en.wikipedia.org/wiki/Foreig...rveillance_Act
To get a warrant under "traditional" FISA the DoJ would have to provide "probable cause" that Carter Page was acting as an agent of a foreign power. This has to be renewed every 90 days and on re-submission you cannot use the original basis on which you submitted the warrant you must provide additional justification. The FBI/DoJ submitted the first application in late October a couple of weeks before the Presidential election. The fact that they did so never surfaced before the election when you would think the win it for Hilary guys would be leaking it like a sieve. They then submitted a further three applications to extend. Apparently each time to a different judge!
The last application was authorised by Rod Rosenstein. This is the only mention of him in the Nunes memo. On the basis of this mention Trump is apparently casting doubt on his fitness to remain in post. The fact that he has oversight of the Mueller enquiry into "No collusion, definitely no collusion" and putting someone in place who may be more inclined to shut down Mueller is probably co-incidental.
There is copious amount of information about Carter Page including a lot of MSM if you care to google him, including details of the amount of times he took the 5th amendment when appearing in front of the intelligence committee.
On thing you may wish to ponder though is why Nunes, when compiling his kitchen sink of sins, made no mention of the type of warrant used. He had just been instrumental in reauthorising the use of warrantless FISA 702 surveillance, presumably by the same agencies he was attacking as politicised. He should therefore know the difference and be able to understand whether the correct process was used.
I know this is getting technical but facts sometimes are though I appreciate they are no substitute for wild unsubstantiated dot-joining. Good luck waiting for your next original thought.