Ah, yes, setting precedent for the Democrats, the party famous for learning from their defeats.
Turek winning would show that there's no strategic downside to his politics in Iowa, or if I'm being really generous, in races to replace incumbent Republicans. The US isn't a political or cultural monolith, campaign strategies vary from state to state, even in presidential elections. For example, Talarico's Christian faith is a boon for his campaign in Texas, but if he wins, it doesn't mean that every candidate across the nation is going to embrace Christianity.
There are no good Republican politicians; two more years of a Republican majority means two more years of unchecked efforts to erase trans people from existence. There are good Democratic politicians; Turek is not one of them. But if I can choose my enemies, I'd rather spend the next two years fighting against him and those like him in a Democrat-controlled Congress than fighting against whatever fresh hell the Republicans have planned for all of us.