If Hillary Clinton had lost Pennsylvania Tuesday night, she would have been out of the race for the Democratic presidential nomination — not merely because she had suffered a humiliating defeat in a state where the New York senator she was supposed to win but because she simply would not have had enough money to continue campaigning.

The Clinton camp finished the bruising six-week fight for Pennsylvania in debt. It had spent at least $1 million more than it had in the bank in order to keep campaign ads on the air in the Keystone state contest with Barack Obama. (A pre-primary report said Clinton had $9 million in the bank and owed $10 million. Obama had $42 million banked with debts of less than $1 million.)

A Pennsylvania defeat would have left Clinton out of campaign cash and out of prospects for raising enough money to compete with Obama’s wealthy campaign in Indiana, North Carolina and other states that have yet to vote.

Even a narrow win would have made it hard for Clinton to get her campaign out of the red and into position to campaign in later primaries.

But the impression that she had won by double digits — it initially looked like she had secured a 55-45 victory in Pennsylvania, although the final results are closer to 54-46 — was enough to get her supporters writing checks.

By Wednesday evening, the Clinton campaign was claiming that it had raised $10 million in 24 hours, with much of the money coming via the web in what Clinton campaign chair Terry McAuliffe referred to as a “historic outpouring of grassroots support.”

The campaign says the cash came from 60,000 donors.

Significantly, 50,000 of the checks came new contributors — meaning that Clinton will be able to go back to them for more money if she wins Indiana on May 6.

McAuliffe says the campaign now “will have the resources needed to compete and win as we move ahead to the next contests.”

That’s critical for Clinton, whose campaign has embraced a sort of guerrilla warfare strategy that relies on one primary win to secure the resources necessary to gain the victory.

This approach is only sustainable if Clinton keeps winning. A serious defeat in a state she’s expected to win, or a string of losses in competitive contests, will slow the money down. And then she’ll be out. But if she keeps winning enough primaries to maintain the cash flow, she will keep campaigning — no matter what her eventual prospects for securing the nomination may be.

Why?

Clinton is not looking to knock Obama out of the running. She knows the Illinois senator will win more primaries in May and June, and that he will finish with more pledged delegates to the convention in August. Her goal is simply to stay in the running in hopes that Obama will stumble — or, more precisely, be tripped. Then, the Clinton thinking goes, she alone will be in position to seize the opening.

It’s an unlikely scenario. But this is guerrilla warfare. And Clinton now has a strategy — and the resources she’ll need — to begin implementing it.