It was his first day back in Washington after a long winter break, and Speaker Mike Johnson was under pressure to pass a short-term funding bill to avoid a government shutdown within days.

With hard-right Republicans in full revolt over the plan, everyone in the Capitol was eager to know what the inexperienced leader would do next, and whether it might lead to his ouster.

After spending less than six minutes answering questions at a news conference, Mr. Johnson shut down reporters’ shouted questions with a silent cue, like a cab light switched off, signaling he was no longer available: He held his smartphone phone to his ear and speed-walked out of sight.

It is a ploy that Mr. Johnson has used frequently to dodge questions since the fall when he won the position of speaker, and with it the tricky job of governing with a deeply divided and shrinking Republican majority in the House.

Before he was elected in October, Mr. Johnson, a Louisiana Republican in his fourth term, routinely stopped for hallway interviews. They are a staple of a lawmaker’s life on Capitol Hill, where credentialed reporters roam freely in all but a few secure spaces, buttonholing members of Congress wherever they can find them. Mr. Johnson would often stop and talk in the marble corridors surrounding the House floor, submitting to impromptu and sometimes lengthy question-and-answer sessions with reporters before and after votes.

But since winning the gavel, Mr. Johnson has taken to avoiding that ritual, employing one of the most common tactics in a member of Congress’s playbook to do so: talking, or pretending to talk, on the phone. These days, as he strides through the Capitol from his office to the House floor and back, Mr. Johnson’s preferred posture is inaccessible. And it most often involves using his iPhone as his buffer.