No, they really don’t care and you’re deluding yourself.
https://www.mediaite.com/tv/cnns-harry- ... years/amp/
“CNN’s Harry Enten predicted Republicans will walk away from the November midterms with a huge majority in the U.S. House of Representatives and argued the party is in its best midterm position in more than 80 years.”
According to the most recent 2022 generic polls on FiveThirtyEight, Republicans have between a 2 and 10 point advantage in the midterms. It varies widely by region. Some of that advantage lies in Red States that aren't likely to shift anyway, but it's likely the Democrats will see some losses. The Jan 6 hearings may not affect that much, except for the few cases of Trump hardliners who may be figures in the hearings.
The issue likely to be affected by the hearings is the split in the polling between popular opinion and Republican opinion on Trump returning to office. He is still the frontrunner of the 2024 Republican candidates, by a wide margin, while having highly unfavorable ratings for the general public.