The six-week Pennsylvania primary drew to a contentious finish Monday as Senator Hillary Rodham Clinton invoked images of Pearl Harbor and Osama bin Laden in a television advertisement that questioned Senator Barack Obama’s ability to lead in a crisis.
As she sought to spark a comeback in the Democratic nominating contest, Mrs. Clinton warned voters not to “take a leap of faith or have any guesswork” when they cast ballots Tuesday.
The Obama campaign accused her of employing “the politics of fear.”
With 158 pledged delegates at stake in Pennsylvania, the largest state remaining on the party’s primary calendar, the candidates raced from Scranton to Pittsburgh to Philadelphia — and a smattering of suburbs along the way — to rally their supporters and win over a dwindling lot of undecided voters.
While Mr. Obama spent nearly twice as much on television advertising in the state as Mrs. Clinton in the final days of the race, she broadcast a new commercial that used historic images from critical moments in the country’s past to ask voters whom they could trust in the White House. It did not mention Mr. Obama, but closed with “Who do you think has what it takes?”