It’s a competitive seat, not a red seat. The last election before redistricting had the Republican winning 52/48. Trump only won this district by 1 point. In a special election, because they are so low turnout, all it takes to win a seat is finding one issue that motivates a small demographic & it can pull them over the finish line. In a normal election (i.e. non-special election this won’t happen. In normal elections messages have to be crafted to a muchhhh bigger electorate & random issues will get lost in amongst a hundred different issues. If it were an election where state legislativ/Governor races or city council/mayor/school board races or Congress/President races were being held, 90+% of the electorate wouldn’t be making a decision on an issue like this. So special elections can really be winnable by people or political parties in areas that would normally never elect them. That’s why most of the winners of special elections, who managed to flip a seat, end up losing in the next normal general election 😉
Thanks for your perspective on this! :)