MORRISVILLE, Pa., - Republican presidential hopeful Mitt Romney made a final-stretch campaign stop on Sunday in Pennsylvania, a Democratic-leaning state where polls show he has been gaining on US President Barack Obama before Tuesday's election.

"The people of America understand that we are taking back the White House because we are going to win Pennsylvania," Romney told a raucous outdoor rally in the suburbs of Philadelphia, where a crowd estimated by the Secret Service at 30,000 had waited hours to see him on a cold evening.

The mid-Atlantic state offers a trove of 20 Electoral College votes, which would be invaluable to Romney as he tries to amass the 270 needed to win the presidency.

His campaign portrayed the foray into the state as evidence that support for the Republican is growing even in unlikely places. But Obama's team said it shows Romney is desperate as he trailed in polls in some key swing states.

Please LIKE our Facebook page - it makes us stronger