new york senator tim kaine virginia emerge online bet favorite presumptive democratic presidential nominee hillary clinton run mate bernie sanders chance slip online predictions market predictit say kaine top list potential vice president candidates 20 percent probability follow u.s. senator elizabeth warren massachusetts 17 percent u.s. labor secretary tom perez 14 percent website allow users wager small amount money say sanders chance join clinton race white house 10 percent big election win tuesday catapult clinton victory sanders u.s. senator vermont although vow go contest race bet clinton win nov. u.s. presidential election go 66 cents bet donald trump presumptive republican nominees trade 33 cents republican side u.s. senator jeff sessions alabama lead race trump run mate 20 percent follow u.s. senator joni ernst iowa 17 percent former house speaker newt gingrich 15 percent new jersey governor chris christie percent late opinion poll reuters/ipsos tuesday show trump trail clinton 10 point 2016 presidential campaign show little change week ago online survey 44.3 percent likely voters say would vote clinton compare 34.7 percent would support trump 20.9 percent say would vote either candidate predictit jointly run washington political consultancy aristotle victoria university wellington new zealand users register u.s. voters opinion poll predictions market always accurately forecast outcome senator tim kaine online favorite run clinton