U.S. Sen. Robert Menendez (D., N.J.) beats potential Republican challenger John Crowley, 45 percent to 26 percent, in a hypothetical matchup, according to a Fairleigh Dickinson University poll released Tuesday.

But Menendez continues to suffer from low name recognition, and voters know even less about Crowley, who has yet to declare his candidacy.

About half the voters polled said they had not heard of Menendez or had no opinion. Polling director Peter Woolley said Menendez recently had improved his low profile, particularly among members of his own party.

Crowley, a biotech executive from Princeton, has flirted with running for the Senate but has made no definitive plans. Ultimately, Gov. Christie would have the most influence on naming the Republican challenger.

Menendez, a former congressman, was first elected in 2006. He faces reelection in 2012, when President Obama is expected to lead the Democratic ticket.

The poll of 804 registered voters was conducted between May 16 and 22 and has a margin of error of plus or minus 3.5 percentage points.

Contact staff writer Cynthia Burton at 856-779-3838 or cburton@phillynews.com.