In the past, Republicans have highlighted Menendez's involvement in a 2006 federal investigation into a New Jersey anti-poverty agency that has ties to the senator. Then-U.S. Attorney Chris Christie launched that investigation while Menendez sought a full term in 2006. During that campaign, Republican nominee Tom Kean Jr. repeatedly reminded voters of Menendez's history with Hudson County politics. Still, Menendez went on win the seat, 53 percent to 44 percent.
Expect Republicans to bring up Menendez's past repeatedly. No one has officially declared their candidacy, but potential contenders aside from Kean include Lt. Gov. Kim Guadagno (R), state Sen. Michael Doherty (R), state GOP Chair Jay Webber, Jets owner Woody Johnson, businessman John Crowley, and state Sen. Joe Kyrillos (R).
None provide a real threat to Menendez yet, according to an early Fairleigh Dickinson University survey. That poll, conducted in January, shows Menendez leading Kean 44 percent to 34 percent, Doherty 40 percent to 30 percent and Guadagno 47 percent to 26 percent.
The poll showed Menendez below the normally-critical 50 percent mark deemed healthy for an incumbent. But New Jersey voters are notoriously unwilling to answer pollsters; high rates of undecideds frequently exist until the final weekend of an election. And don't forget President Obama, who won New Jersey by 15 points in 2008. If Obama's popularity in New Jersey in 2012 remains high, his coattails can help Menendez.
"The presidential year electorate, with a Democrat winning by so much on the top of the ticket, really is a big benefit to all the Democrats below on the ticket," Republican strategist Mike DuHaime said in an interview.
And as Kevin Brennan recently pointed out, while Menendez's most recent polling numbers aren't stellar, the fact that New Jersey hasn't elected a Republican senator since 1972 also bodes well for Menendez's chances at reelection.