Mike Mikus, a veteran Democratic consultant based near Pittsburgh, said the ferment among conservative news outlets reflected the fact that to win a modern Republican primary, “You don’t need the traditional press.”

For instance, the campaign of Doug Mastriano, a leading Republican contender for governor of Pennsylvania, rarely responds to queries from mainstream news organizations, and has barred journalists working for The Philadelphia Inquirer, the state’s most influential source of political news and commentary, from its events.