No, they can not cross party lines. The NH law states that Undeclared/Independents can vote in either Dem or Rep primary. Then they can change back to Undeclared after voting.
A registered Democrat can NOT vote in the NH Republican primary.
A registered Republican can NOT vote in the NH Democrat primary.
That is the law in the State of NH.
I realized my error after posting it.
Yes, but will the law be followed, or just ignored ?