Democratic President Joe Biden has made abortion a cornerstone of his campaign going into November, but its effect on his re-election chances is less than certain, according to political experts who spoke to the Daily Caller News Foundation. Julie Chávez Rodríguez, Biden’s campaign manager, said in June that they were going to be putting abortion “front and center” leading up to the election, and Biden and Vice President Kamala Harris have since been active on the campaign trail at rallies across the country focusing on the issue. The president also invited Kate Cox, the woman at the center of…