It does make you wonder. Minority and migrant communities actually have a lot of conservative values. If the GOP was seen as all encompassing, they'd should regularly smash Democrat candidates. Unfortunately, there's a long history of coded rhetoric, that makes minorities/migrants believe they aren't welcome.
This is one of those things that conservatives find endlessly frustrating and I don't really know what we can do about it.
I used to participate in some online forums about the American Civil War that include people from all political backgrounds. I found that it was impossible to have a discussion of the history of "states rights" regarding the role of the federal government versus the states. If I even appeared to have any view of that role that could be interpreted as sort of sympathy towards the Confederacy I was suddenly speaking in code about how I wanted a return of Jim Crow, slavery, etc. I found it flabbergasting that anyone could believe that I actually wanted that just from trying to discuss the constitutional role of government in the 1860's and the part it played in the conflict.
I agree that too many Republicans have a history of saying stupid things, but I find it incredibly difficult to have any discussion with people that insist everything I say is some sort of code for something else. Unfortunately, Democrats have long seen how they can profit from it, and Republicans haven't figured out how to combat it.