Democratic Rep. Krysten Sinema is leading all her potential Republican opponents including Rep. Martha McSally. A new poll from ABC 15/OH Predictive Insights shows Sinema leading McSally by 4 points in the race to replace retiring GOP Sen. Jeff Flake. The race offers Democrats one of the best pickup opportunities in fall’s midterm elections. Democrats generally face an uphill battle in Senate race where 10 races are taking place in states which Donald Trump won in 2016. In the same poll, Sinema also leads right-wing Republicans Kelly Ward (+10) and Joe Arpaio (+18).