The Clinton campaign has been mostly kept afloat by loans from the Clintons(Bill and Hillary) for quite some time now, she has loaned herself over $11 million. This money mostly came from Bill Clintons income as a paid speaker. The question becomes how much of his speaking fees were paid by people who knew that money would go to help Hillarys campaign. In effect, it is possible that the Clintons have been able to finance their campaign by only using a few donors that paid hi speaking fees, these fees would go to Bill Clinton who could then “loan” all the money he wants to his wifes campaign. Â
This is similar to the issue John McCain faces where he opted into public financing and then out of it with personal loans. This is a very effective issue against John McCain as he probably violated his own campaign finance law.  However, if your choice for VP violated the same law, or even appeared to violate the law, it would not be an issue that can be raised. At least not without looking like a hypocrit.
I don’t think the unity ticket is that serious of an idea any way, but it would be a bad idea if anyone is seriously considering it.