Insiders tell the New York Daily News the only way Clinton will drop out soon is if she loses today in Pennsylvania and runs out of money. Speaking of which, it’s reported that Clinton’s campaign is in debt to the tune of several million dollars.

Which refers to 'runs out of money'?
I'd say which refers to "money," but you can just as well say it refers to "runs out of money." I don't think it makes any difference gramatically. It just depends on what the writer had in mind. You often must wait to see what he writes next, since he may have been speaking of many things.
That's a good question. I would think it refers to the thing closest to which, which in this case is out of money. Let's wait for a native to confirm.
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 Avangi's reply was promoted to an answer.
New2grammarout of money
You might be right. Thanks, New2.
AvangiI don't think it makes any difference gramatically
I didn't notice your post, Avangi. Sorry.

I understand. I agree with you .Thanks, Avangi.
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