They're right. Of the listed grievances, only gerrymandering is a bipartisan issue, and even then only Conservatives have fought to preserve and expand its use.
MA: 36% Republican, 0 seats CT: 42% Republican, 0 seats ME: 46% Republican, 0 seats NM: 46% Republican, 0 seats NH: 48% Republican, 0 seats RI: 42% Republican, 0 seats VT: 32% Republican, 0 seats HI: 38% Republican, 0 seats DE: 42% Republican, 0 seats
Rucho v Common Cause, a case brought against both Dems and GOP that would have rightfully declared partisan gerrymandering an unconstitutional deprivation of voting rights, was shot down by a Conservative court. Democrats campaign on ending gerrymandering, Republicans do not. Trump demanded the recent escalation in gerrymandering by explicitly calling for political re-drawings to give Republicans more seats, and Republican governors complied. The calls to de-escalate and ban the practice federally have (almost) entirely come from Democrats.