It’s not new for incumbents to stump for fellow incumbents. Even the Congressional Progressive Caucus has a policy against endorsing challengers to sitting representatives, despite a number of its own members being elected after successful primary upsets. But a faction of the left says when it comes to members of leadership, the rules should be different.

“It’s a disturbing pattern, frankly,” said Maurice Mitchell, national director of the progressive Working Families Party. “And we think that Democratic leadership kind of putting its thumb on the scales specifically, consistently, to purge progressives from the caucus, is short-sighted.”…

In many deeply blue congressional districts, Democratic incumbents often coast through re-election cycles with little difficulty and remain in office until they willingly retire. That is, unless they have a viable challenger, many of which are unwilling to merely wait for an opening.

These districts, in particular, should be off-limits to leadership meddling, progressives in this space argue, given that a Democrat will likely win the general election regardless of the primary outcome. And in a year where House Democrats are forecast to face difficult general election prospects this November, Shahid pointed out, there are better places for party leadership to spend their time.