Kamala Harris’ run for the white house is posing new challenges for down-ballot candidates, including a number of Democrat Senators up for re-election. Harris’ emergence as the party’s likely presidential nominee is creating some new angles of attack for Republicans hoping to flip the Senate. Key Republican targets include Sens. Jon Tester (D-Mont.), Sherrod Brown (D-Ohio), Bob Casey (D-Pa.) and Jacky Rosen (D-Nev.) . All will have to face questions about VP Harris controvdersal policy position dating back to the 2020 Democratic primary. Many of her statements lean hard to left on topics ranging from the border and immigration, to “Medicare for All”  and  and opposition to the Keystone XL pipeline.