Why redistricting (gerrymandering) structurally favors Republicans

The population of the U.S. has been increasingly moving southward so, yes, states in the South and Texas (Texans don't like to be lumped in as part of the South) will be gaining not only Congressional representation after the 2030 Census but more electoral votes as well.

I've mentioned this in the past as to why it is imperative that Democrats do more at the STATE level, because that's where the Congressional maps are created in Republican-controlled states. And it is in Texas and Florida where gerrymandering has most effected the state legislatures with Republican majorities far in excess of voter registration and presidential popular votes in those states.

Democrats needed better candidates at the legislative state level that can compete despite being at a disadvantage in districts favoring Republicans because that's the only way they'll begin to address the imbalance. But the national party feels that's a waste of resources.

@ElwoodBlues

Take a good look at the green Democratic-controlled states.
CT (5/5 House seats are held by Democrats), (MA (9/9 Dem), RI (2/2 Dem), WA (8/10 Dem), NJ (9/12 Dem) NY (19/26)

Or the yellow Democratic controlled states ME (2/2 Dem), MD (7/8 Dem), CA (43/52)

They‘re maxed out, okay? They can’t change the fact that rural East California is conservative or that rural upstate New York is conservative. They have to put those voters somewhere and they are already in as few districts as possible.

There‘s not one toss-up for the Democrats in either New York or California at the moment.Republicans, however, are very competitive in CA45 (Orange County) and NY4 (Nassau county).

There are two competitive seats in NY for Democrats. But if they were too infuse them with more Democrats they‘d be forced to shift some of the red population to a swing district that’s competitive for Republicans.
So if Democrats were to move more people from NY16 up north to NY17 (Rep Mike Lawler‘s (R) district), then they‘d have to move some Republicans from NY17 further up north to NY18 which his currently held by a Democrat but only leans Democratic and would turn into a toss up if they pursued that redistricting strategy.

As I‘ve said, the effective congressional representation to vote share is worse for Republicans in New York, New Jersey, Illinois, Washington, Maryland and Massachusetts than it is for Democrats in Texas, Florida, Ohio or Georgia.

People have come up with algorithmic methods to measure the degree of gerrymandering. And it turns out that republican controlled states are just far more blatant about their gerrymandering.

See https://gerrymander.princeton.edu/redistricting-report-card/

Most of the gerrymandering seen in the map happened before SCOTUS ruled that gerrymandering was perfectly legal, so maybe in the next redistriicting cycle the blue states will start to be blatant too.

The system producing this is not condoned or sanctioned

Failing system not protecting that construct, that is a no reset