The drunk doesn't have enough or your dad? If it's the drunk, then dad should go for his underinsured motorist coverage. If the drunk had no insured, then uninsured motorists coverage.
He can try suing the drunk driver, but usually they don't have any assets.
If there still isn't enough, he should ask the hospital about Hill Burton funds. The federal government gives money to hospitals for building if they treat a certain number of patients for free. They just never tell the patients.
Otherwise, he will have to try to work out something with the medical providers or declare bankruptcy.
And in your spare time, contact your representatives about voting FOR the health care bill so this won't be a problem in the future.