While the focus remained largely on the Senate race, appearances by Sens. John McCain and Hillary Rodham Clinton also looked like a potential preview of the 2008 presidential campaign.
McCain, R-Ariz., told roughly 250 donors at a Kean fundraiser that he believed the Garden State contest would determine which party controls the Senate. Democrats are seeking to pick up six seats to take control.
"The eyes of America will be upon this race, and I think they have a very clear choice," said McCain, who described Kean as a "reformer."
Later Sunday, during a speech in Paramus, Clinton, D-N.Y., touted the work Menendez has done — particularly his efforts to bolster homeland security — since Gov. Jon S. Corzine appointed him in January to complete his Senate term.
Noting that Menendez was a vocal critic of the Bush administration's plan to let a Dubai-owned company buy a stake in several U.S. ports earlier this year, Clinton told the crowd of about 700 people that "Bob wasn't intimidated, he didn't back down. He stood his ground and we finally beat them (Bush administration) back."
McCain and Clinton have both been the subject of rampant speculation over whether they will seek the White House in 2008. McCain said Sunday he would make a decision early next year. Clinton, speaking earlier during a debate in her own Senate race, refused to disclose her plans, saying she had not made up her mind.
Recent polls show the New Jersey race remains close.
A Monmouth University/Gannett New Jersey poll released Sunday showed 48 percent of likely voters favoring Menendez with 39 percent favoring Kean. The poll of 396 likely voters, conducted by telephone from Oct. 16-19, has a sampling error margin of plus or minus 4.9 percentage points.