One district , PA - 03 , was extremely close , however , with McCain only winning by less than 20 votes .
Although Barack Obama won Pennsylvania , John McCain carried 10 of the commonwealth 's 19 congressional districts , including four districts held by Democrats .
One district , Pennsylvania     , was extremely close , however , with John McCain only winning by less than 20 votes .
Although Barack Obama won Pennsylvania , John McCain carried 10 of the commonwealth 's 19 congressional districts , including four districts held by Democrats .