Sen. John McCain will face a challenge from the right in next year's Republican primary, as one of the country's most prominent border hawks will announce his candidacy for Arizona's Senate seat on April 22. Chris Simcox, who founded the Minuteman Civil Defense Corps, will file campaign paperwork today to formalize his challenge of McCain, who has angered conservative Republicans for his stances on a variety of issues - most prominently, illegal immigration and border security. Simcox will represent a stark contrast in Republican ideology compared to that of McCain, said Eric Johnson, a senior advisor to Simcox and former...