I think South Carolina will be the first real opportunity for Marco Rubio to shine. Walker will primarily focus on Iowa and Florida, Christie will focus on New Hampshire and Florida, Paul will be heavy in all four states, and Rubio will try to focus on the more traditional GOP voters in the south.
Florida isn't one of the early states anymore.
I stand corrected. That hurts Rubio, and maybe Walker too, but helps Paul out, because he'll do very well in Colorado. Walker will do well in Minnesota, so it may be a wash for him.
I still think Rubio does well in South Carolina. What I meant by traditional GOP voters is the more mainstream, pro-military socially and economically conservative wing of the GOP, more akin to a George W. Bush than a Ron'/Rand Paul. Rubio is ideologically very post-Reagan/pre-tea party GOP, which I think plays well throughout the south.