State Field - Conditional logic

This would be possible using conditional logic. You would have to add a Drop Down field, populate it with the states. You can use the bulk add/pre-populate functionality and select US States so you don't have to type them all.

Then you can add an HTML block directly below that field where you display the "Sweepstakes only available..." message and go to the Advanced tab and use conditional logic on it to only show it if the state selected is one of the states where the sweepstakes isn't available.

Then create a Section Break just below it and before the sweepstakes fields themselves. Use conditional logic on that Section Break to only show that section of fields if certain states are picked.

What this will do is it will show the HTML block if a non-eligible state is selected, and show the Section Break and all fields under it if the state selected is eligible.