I bet that in practice that happens pretty rarely because it's risky (what if the legislator has cameras you don't know about, etc).
But I think politicians understand that capital and the national security state are very influential, and their careers will go much better if they do their bidding (without anyone ever explicitly asking them to). They'll find it easier to get elected, less interference from courts, great consulting and speaking gigs after they retire, and so on.
House speaker Johnson, once becoming speaker, did a complete 180 on many of his policies, and even cited his closed door SCIF briefing with Intel agencies as to why it became such a huge priority to push through the FISA garbage. This is the same briefing that many other politicians have had, and continue to fight against these 4th amendment violations. Hard to believe that these briefings aren't actually threat sessions when it comes to politicians that are pivotal.
But I think politicians understand that capital and the national security state are very influential, and their careers will go much better if they do their bidding (without anyone ever explicitly asking them to). They'll find it easier to get elected, less interference from courts, great consulting and speaking gigs after they retire, and so on.