They didn't start it. You deny the history of gerrymandering.
They are "retaliating" based off of a lie (that gerrymandering "started with Texas"). This is a war that, IF Republicans wish to win, then Democrats CAN'T win.
There are several states out there that are controlled by Republicans that plan on redistricting before the 2026 midterm elections. Even MORE of those states will do so if SCOTUS makes a particular ruling regarding the VRA.
Are Democrats going to "retaliate even more" when that happens? What states would retaliate? (Hint: Democrats have already fully [or near-fully] gerrymandered most of their states)