According to
Richard Winger, he could make about 1/3 of the states without a legal challenge, and get to almost half with successful legal challenges. Some of these are completely unrealistic though, like California, where they would need 178039 petition signatures in 4 days. Commenter Jeff Becker thinks that these 13 are the realistic ones:
Alabama (5000 signatures in 10 days)
Colorado (super easy - only pay money - but only have 2 days)
Kentucky (5000 signatures in 1 month)
Louisiana (super easy - only pay money)
Minnesota (2000 signatures in 2 weeks)
Mississippi (1000 signatures in 1 month)
Montana (5000 signatures in 9 days)
North Dakota (4000 signatures in 1 month)
Rhode Island (1000 signatures in 1 month)
Tennessee (275 signatures in 10 days)
Utah (1000 signatures in 1 week)
Virginia (5000 signatures in 2.5 weeks)
Wyoming (3302 signatures in 3 weeks)
Looks like the political party will be a mix of Independent and "Better for America." Does he have a running mate yet?