President Trump’s advisers have concluded that a wide-ranging corruption investigation into his personal lawyer poses a greater and more imminent threat to the president than even the special counsel’s investigation, according to several people close to Mr. Trump.

As his lawyers went to court in New York on Friday to try to block prosecutors from reading files that were seized from the personal lawyer, Michael D. Cohen, this week, Mr. Trump found himself increasingly isolated in mounting a response. He continued to struggle to hire a new criminal lawyer, and some of his own aides were reluctant to advise him about a response for fear of being dragged into a criminal investigation themselves…

Mr. Cohen has publicly declared that he would defend the president to the end, but court documents show that prosecutors are building a significant case that could put pressure on him to cooperate and tell investigators what he knows…

Prosecutors demanded all communication with the campaign — and in particular two advisers, Corey Lewandowski and Hope Hicks, according to two people briefed on the warrants.