Minnesota Gov. Jesse Ventura's choice of longtime ally Dean Barkley as temporary successor to the late Sen. Paul D. Wellstone (D-Minn.) gives the Senate a second independent member and adds to the uncertainty over which party is likely to control the narrowly divided Senate in a post-election session scheduled to start Nov. 12. Barkley, 52, is one of Ventura's closest advisers and a co-founder of the state's third-party movement. He helped persuade Ventura to run for governor in 1998 and managed his campaign. He ran twice for the Senate as an independent and, while losing, drew enough votes to put...