Mitt Romney’s stretch run push in states that have appeared to favor President Obama is a reflection of an expanding electoral map, senior Romney adviser Ed Gillespie said Sunday.

“When you look at where this map has gone, it reflects the -- the change and the direction and the momentum toward Governor Romney," Gillespie said on ABC’s “This Week With George Stephanopoulos.” "And the fact is that a state like Pennsylvania being in play, a poll out today showing Michigan a dead heat, you know, this -- the map has expanded,” 

Democrats have cast Romney’s push in Pennsylvania as a desperation effort. Romney is stumping in the Keystone State on Sunday, as recent polls have shown a tightening race there. Gillespie said the Romney campaign’s effort in Pennsylvania has not strained its resources in other key swing states.

"Wisconsin, Minnesota has expanded our way," Gillespie said. "We feel very confident in terms of where we are in the -- in the target states. We've been able to expand into Pennsylvania while fully funding and staying current with everything we need to be doing in Florida and Virginia and Ohio and all of the other target states."