.How do you compete in a Republican primary for a border state Senate seat? Martha McSally is offering one clue. The Arizona congresswoman took to the House floor last week to ask unanimous consent to remove her name from a bill that would provide legal status and an eventual path to citizenship to some children of undocumented immigrants. Until then, McSally was one of 34 Republicans to co-sponsor the Recognizing America's Children Act, seen as a new and conservative version of the DREAM Act. The only Democrat to sponsor the bill is fellow Arizona Rep. Kyrsten Sinema, whom McSally hopes...