Like I mentioned, this is literally the definition of realpolitik.
realpolitik - a system of politics or principles based on practical rather than moral or ideological considerations.
The determination so far seems to be that the harm in keeping Santos is less than the harm in getting a Democrat to replace him.
And that could change. It looks like a fluid situation.
Honestly, I'm not too worried about it. All of those considerations went out with the baby, the bathwater, and the kitchen sink when Obamacare passed on a party line vote with the individual mandate. You throw in what Biden has done with the absolute chaos on the open border and there is just no possible way that any harm Santos could possibly do either by actions or impingement of the reputation of the party, can add up to the damage that having another Democrat in Congress can do to the country. Democrats made the same Faustian bargain when the elected Joe Biden.
I'm a firm believer in relationship and political reciprocity, in not to my detriment holding myself to higher standards than political adversaries would would use those standards against my party to achieve their own goals while they completely violate them themselves. Biden is a hundred times worse than Santos, at least. I'll worry about Santos when Democrats turn on Biden and remove him from office. Until then, it's just not a big concern. If the powers that be in the Republican Party decide he's a liability and needs to be taken out, then so be it. I won't cry for him, but I'm not going to attack him either. I'll trust leadership to do what's best for America, and that may be forgiveness and rehabilitation, supposedly concepts of merit with the left.