Why not if they like that republican better than the choice of independents and democrats? Why not accept all the help we can get in defeating the democrats??
Independents and democrats are Americans too.
They may be Americans but they are not Republicans. These are party caucuses and primaries to choose the candidates the parties will field in the fall. Independents can choose to vote for whomever they will in the general election. They can vote for a major party candidate or a candidate from a small party. They can form a new party or they can write in their uncle Joe. What they can not do, in many states, is vote in the primary of a party they do not belong to.