Gerrymandering can help Republicans in the lower chamber† but it can't help in the Senate where they're most scared. Every voter in Texas gets to decide whether to pick Ken Paxton or James Talarico and perhaps more importantly if they can't stomach voting for somebody with a D next to their name, they can decide they were too busy that day to go vote at all so it's not really their fault.

† But it might not, if you turn five 7/3 R seats and two 9/1 D seats into six 6/4 and one 9/1 you risk a dummymander where too many of "your" voters vote the "wrong" way and you have seven Democrats elected even though you still took almost 50% of the vote in some districts and you drew the maps.

Now the trouble is that voters seem to be imagining that if the Democrats take the Legislature that's the whole ball of wax and it just isn't. If there's a narrow D majority in both parts of Congress you can expect that to stall the stupidest stuff from Trump which was subject to congressional oversight, but the useless "We need bipartisanship" mewling will start almost immediately from people who apparently were 100% fine with party-line Republican decisions or executive override.