I only know libs who do this in states where you don't have to be registered with the party to vote in the primary. I do know democrat voters who are registered Republican, not because they are libs but because the Republican party of today is too insane for them. But they still want to vote in R primaries because they want the "fiscally responsible" Republican party back.
I wouldn't assume anything. That just means they voted in the Republican primary.
It's not an uncommon idea among libs to vote in the opponents primary to pick the option least-bad option.
I only know libs who do this in states where you don't have to be registered with the party to vote in the primary. I do know democrat voters who are registered Republican, not because they are libs but because the Republican party of today is too insane for them. But they still want to vote in R primaries because they want the "fiscally responsible" Republican party back.
This is purely anecdotal though so 🤷♀️