It might be too late for this suggestion but a thought.
I think it would be best to indicate Jews Against Obama with signs that indicate that Obama is evil for the Jewish people and Israel and the US and sight obvious things that make him terrible...for example, his life long reverend, his willingness to talk to Muslim Nazis who wish genocide on Israel, and etc. Mainly things focusing on how he would be a terrible president for Jews and Israel because he will negotiate with Arab Muslim Nazi terrorists. It might catch some peoples' eyes..