As further evidence of gerrymandering’s lock on the political landscape, four of San Antonio’s five congressional districts look to be unchanged in Tuesday’s election. And the one that switched hands is still controlled by the same party. In the case of the single district that gained new blood — the 35th, comprised of both central Austin and downtown San Antonio — that switch came after its longtime U.S. Rep. Lloyd Doggett, a Democrat, opted to run in another district.