Negative ads are used because they can have the desired impact for the person behind it. The latest Hillary ad goes after Obama's position on NAFTA. In public he had said it wants it to be renegotiated, but her ad alleges that he said in a private conversation, that his words were just for political purposes. Hillary bounced on this. In a statement to the media, she accuses Obama of double-speak, telling Ohio voters one thing about NAFTA, and telling the Canadian Consulate in Chicago another thing about NAFTA.
From this site
A memo obtained by The Associated Press suggests Obama's economic policy adviser privately told Canadian officials to look at the Democratic candidate's attack on free trade as "political positioning" rather than policy.
Obama's camp says it was not his words but rather a staffer's interpretation.
This information may have been planned for days, and her team waited till today, the day before four primaries Tuesday, to spring the ad, and leaving the Obama team little time to defend, and try to counter the attack. This could sway some votes her way, unless his defense and response are strong and neutralize her ad's message. At this time, her allegation seems strong. It leaves doubts about Obama. The timing of her ad at the 11th hour is evidence that Texas and Ohio are crucial battlegrounds for Clinton. Even a narrow win for her will give her the momentum she has been lacking for over two months, and she will stay in the race till April's next primaries.
The polls are a statistical tie in both Ohio and Texas, 47-43% for Hillary in Ohio, 46-45% for Obama in Texas, with the remaining percentages being undecideds. Hillary will need to win hugely to equal Obama's overall lead in delegates, which is 1379 to 1269. Texas Latinos were a large part of Hillary's support, but Obama appeals to youth, so he may end up getting the "Lateeno" vote, thus stealing from Clinton.
With today's sneak attack from Hillary, and the close polls, it would not be surprising if Hillary does squeak out a win in Ohio and Texas. But, will it be enough to significantly bridge the delegate gap, and give the impression that she indeed has momentum? Will there be basically a 50-50 voter/delegate split, or will Clinton's assertive campaigning entice more voters her way? It's getting interesting again.