KABUL (AP) — Sen. John McCain called Tuesday for more American troops in Afghanistan, saying that doubling the number of Marines in one southern region could lead to "significantly more success." The former Republican presidential candidate, along with other members of a visiting congressional delegation, also said that Afghanistan's elections this week were a milestone event, but that the U.S. was not backing one candidate over another. The group's two-day visit included meeting with Marines in southern Helmand province, where U.S. and Afghan forces are staging a major offensive aimed at clearing out Taliban militants ahead of Thursday's vote.