JACKSON, Miss. (AP) — A Mississippi senator's frail appearance on Capitol Hill this week raises questions that make some of his home-state supporters downright queasy. Is Republican Thad Cochran, the 79-year-old chairman of the powerful Appropriations Committee, well enough to serve the final half of his six-year term? What happens to Mississippi's political clout if he resigns? Cochran stayed home for a month with urinary tract infections, returning to Washington this week to give Republicans the majority they needed to pass a budget plan. Should Cochran resign, Republican Gov.