Rs actually did try the independent strategy once in 2018, and it nearly worked.
But to replicate Murkowski, you'd need to find a Democrat that can:
1) Vote with Rs 40% of the time
2) Break with Ds on many meaningful issues
3) Still win over a substantial number of Ds
Okay, but Democrats use this exact strategy effectively. It’s how they got Lisa Murkowski elected. Democratic primary voters just voted in Nebraska and Montana for the candidate who said they would drop out in favor of a centrist independent candidate.
But GOPers won’t do it.