The thing is that there is no way that can happen. GM has already reported a $4.3 Billion loss at the end of last year, which curiously coincides with payoff the of loan. It just doesn't make accounting sense, what this Senator is spewing hot air about.
Now remember they still have to pay $45 Billion back to the govt, because all that money has been converted to stock. Once they go public later this year, they will be able to pay that off, untill then the govt still owns GM...
http://www.usatoday.com/money/autos/...-gm-loan_N.htm