How can congress pass legislation allowing bankruptcy judges to change terms on already written mortgages?

It seems like this would be challanged (sucessfully) in court since the laws when the contract was signed didnt allow modification. I can understand how they could mandate that future mortgages are capable of being modified but not those already written... seems kinda like ex post facto.How can congress pass legislation allowing bankruptcy judges to change terms on already written mortgages?
1. Ex post facto means that Congress is prohibited from making a law retroactively punitive. i.e. Congress couldn't pass a law saying that drinking is illegal again and punish people who drank before the law went into effect. It affects criminal statutes only.





2. Congress is just being Congress. They know there is a large likelyhood that this can be overturned. They just want to tell peopl that they tried.How can congress pass legislation allowing bankruptcy judges to change terms on already written mortgages?
Because the democrats currently in control of congress don't believe we are smart enough to negotiate our own contracts. While that may be true in some cases, the courts shouldn't be stepping in to alter them.
I'm with you on this.