WASHINGTON (AP) _ Barack Obama built a formidable a lead in his bid to become the first black president Tuesday night, pushing ahead of John McCain in a nation clamoring for change. Fellow Democrats took four Senate seats from Republicans, and reached for more.

Obama gained precious ground in Pennsylvania, winning the state’s 21 electoral votes and depriving McCain of the Democratic-leaning state where he had tried hardest to break through. Obama also swept through territory typically friendly to Democrats in the East and Midwest.