Four states head to the polls: voters in Ohio, Texas, Vermont and Rhode Island vote or caucus today, and in the case of Texas, they vote and caucus. Republican John McCain hopes to seal the nomination, while the Democratic race continues to unfold. More than 400 delegates are at stake for the Democrats, and the campaigning has become fierce in recent days. Ohio and Texas are crucial states to both candidates. Barack Obama hopes for wins to further his lead, while Hilary Clinton needs to win in order to justify a reason to stay in the race. And as the candidates are jockeying for votes, Ohio has undergone a drastic change in their election system, change that is meant to restore credibility in this state's elections. FSRN's Leigh Ann Caldwell reports from Ohio.