She accused Obama, who is still ahead nationally in the Democratic race, of not being able to close the deal even with such a heavy financial advantage.
US exit polls suggest Clinton won by taking the votes of blue-collar workers, women and white men, who Obama is failing to attract.
In the run up to the primary, Clinton took a hard line in her advertising in Pennsylvania, using images of Osama bin Laden and Pearl Harbour in a TV ad that questioned Obama's ability to lead in a crisis.
The latest ad used historic images from critical moments in America's past to ask voters who they could trust in the White House, ending with the line "Who do you think has what it takes?".
It is the first time a Democratic candidate has used Osama bin Laden in the Presidential race, although Republicans have done so.
Clinton also surprised some Democrats in the lead up to the Pennsylvania vote by answering a question posted to her by ABC's 'Good Morning America' in which she said what she would do in a situation in which Iran attacked Israel with nuclear weapons.
She said: "I want the Iranians to know that if I'm the President, we will attack Iran. In the next 10 years, during which they might foolishly consider launching an attack on Israel, we would be able to totally obliterate them."
Obama accused Clinton of employing "the politics of fear" with her advertising and his campaign quickly responded with an ad that asked voters "Who in times of challenge will unite us -- not use fear and calculation to divide us?".
Clinton bounced back in March using another hard-hitting spot dubbed the "Red Phone ad", which helped her win in Texas, Ohio and Rhode Island.
That ad asked Americans who they would want to answer the phone ringing in the White House at 3am.
Clinton's campaign is struggling to raise money, with unpaid bills mounting up, and following her victory in Pennsylvania she urged her supporters to log onto her fundraising website to ensure the future of her campaign.
It is estimated that the Obama campaign has $42m to spend against Clinton's $21m as their respective campaigns head to Indiana and North Carolina in the next stage of the battle with voting on May 6.