Trump and his Chief of Staff John Kelly might have been on good terms at some point, but that's clearly no longer the case.
Sources who spoke to CNN say Trump has stepped up use of his personal cell phone in recent weeks so John Kelly won't know who he's talking to.
During the early days of Kelly's tenure, multiple sources said, Trump made many of his calls from the White House switchboard -- a tactic that allowed the chief of staff to receive a printed list of who Trump had phoned. Kelly has less insight into who Trump calls on his personal cell phone.
While Trump never entirely gave up his personal cell phone once Kelly came aboard, one source close to the White House speculated that the President is ramping up the use of his personal device recently in part because "he doesn't want Kelly to know who he's talking to."
The senior White House official said Trump "is talking to all sorts of people on it," noting Trump's barrage of private calls is a "recent development."
There's obvious concern that Trump using his personal cell phone to hide his calls from the White House means there will be no official record of his conversations, but there are also major security concerns.
Immediately after reading this story late last night, I was reminded of a recent report that the Department of Homeland Security detected illegal cell-site simulators in the Washington D.C. area that were probably used by foreign governments to intercept phone calls.
Cell phones approved and issued by the government include enhanced security measures, but we don't know what if any measures are installed on Trump's personal cell phone or if it's regularly updated.
Moreover, even if Trump's personal cell phone is secure, it's likely that he is calling people (such as Fox News hosts) whose phones are not secure.
It's a fairly good bet that someone out there is listening. Every intelligence agency in the world has good reasons for listening to Trump's conversations. The personal conversations of a president may not ordinarily be all that relevant, but Trump tends to turn his random conversations with ring wing cranks into impulsive policy decisions.