The door is closing:
The filing deadlines are one of the most important barriers to someone entering the race this late. Besides Florida and New Hampshire, South Carolina and Michigan’s deadlines are on November 1 and 15 respectively, and New Hampshire’s filing deadline may be moved earlier to accommodate an earlier primary date. There might still be enough time to meet those deadlines, but that assumes that new campaigns know what they’re doing. Even Perry’s campaign had a lot of catching up to do when he entered the race in August, and learning all the requirements is a time-consuming process
The Dish 