No Democratic incumbent can take anything for granted in this political environment, but Illinois Sen. Tammy Duckworth is the clear favorite to win a third term. Seven Republicans are vying to take on Duckworth, but scant public polling has shown most voters remain undecided. In a poll for the Chicago Sun Times by left-leaning Public Policy Polling conducted June 6-7, two-thirds of voters remained undecided. Only two candidates — attorney Kathy Salvi and Navy veteran Peggy Hubbard — even barely broke double digits with 10 percent apiece.