This rift is between populist Trump supporters and the old conservative establishment. The traditional gatekeepers of conservatism tend to wield wide influence within the Republican Party. The current group of editors, punits, and columnists came to power in the days when George W. Bush was president and the conservative movement looked very different.
The Two Sides of the Divide
Therefore on one hand are the Trump populists, who are focused on elements of a culture war and who back a relatively restrained nationalistic view of foreign policy. They view themselves as being essentially locked out of institutions of governance by the "deep state" and other elements of the permanent government. They view themselves as beleaguered, and as such they employ a more aggressive tone and posture toward those—with the exception of close allies—who presently occupy positions of power. On the other hand are the mainline conservatives, who view themselves as the "reasonable" ones or as "the adults in the room." They are generally comfortable with the status quo and seek a stable political system within which they hope to soon wield power. Unlike the Trump supporters, these conservatives are heavily focused on foreign policy and the frequent and aggressive use of state power in the international sphere. They downplay domestic policy and culture war issues, preferring to instead embrace a position of tepid opposition to the Left's legislative agenda.