Republican presidential nominee Mitt Romney and vice-presidential nominee Paul Ryan gestures to supporters and campaign workers at a campaign office during the U.S. presidential election in Richmond Heights, Ohio November 6, 2012. [REUTERS/Brian Snyder]
FULL FOCUS: Election Day 2012 in pictures

Republican presidential nominee Mitt Romney and vice-presidential nominee Paul Ryan gestures to supporters and campaign workers at a campaign office during the U.S. presidential election in Richmond Heights, Ohio November 6, 2012. [REUTERS/Brian Snyder]

FULL FOCUS: Election Day 2012 in pictures

Seventeen smiling, crying, and happy babies held by Mitt Romney

Mitt Romney hands Madison Busch to her mother after a campaign event at an RV dealer in Loveland, Colorado, February 7, 2012.  REUTERS/Rick Wilking

Defying personal and professional pressures, Rick Santorum is returning to the U.S. presidential campaign trail in his uphill battle against presumptive Republican nominee Mitt Romney.
After a five-day break to celebrate Easter, help care for his sick daughter and thrash out strategy, Santorum kicks off the fight for his home state, Pennsylvania, in earnest on Tuesday.
He needs to win the state by a decent margin to stay in the race against Romney, whose allies have already begun negative TV attacks against the conservative former senator.
READ MORE: Santorum hitting campaign trail again despite pressures

Defying personal and professional pressures, Rick Santorum is returning to the U.S. presidential campaign trail in his uphill battle against presumptive Republican nominee Mitt Romney.

After a five-day break to celebrate Easter, help care for his sick daughter and thrash out strategy, Santorum kicks off the fight for his home state, Pennsylvania, in earnest on Tuesday.

He needs to win the state by a decent margin to stay in the race against Romney, whose allies have already begun negative TV attacks against the conservative former senator.

READ MORE: Santorum hitting campaign trail again despite pressures