Matthew Modine Joins "Dark Knight Rises" Cast

So according to the folks at Nerdist.com, Matthew Modine will be joining the "Dark Knight Rises" cast as the third villain.  In a previous post, John announced the other two in the line up (read all about them here.)  Matthew Modine, you might recognize from Full Metal Jacket, will be playing a character we know now only as Nixon.  It is reported that the character will pay homage to the name as a crooked politician.  So my guess is as good as yours, is this a new villain?  Who in the Bat-Verse could he be?