In a state that hasn’t elected a Republican senator since 1972, Democratic incumbent Robert Menendez would be a shoo-in for re-election if he had not spent much of his current term under fire for accepting gifts from a wealthy doctor whose interests he promoted. His Republican challenger will be Bob Hugin, a former biotech chief executive, and a recent poll showed him trailing Mr. Menendez by just four points.

Read more

Five of New Jersey’s 12 House races are also expected to be competitive in November, and Democrats are focusing on three held by Republicans: the Second, Seventh and 11th Districts. Keep an eye on the Second District, where the incumbent, Frank LoBiondo, is retiring. Jeff Van Drew, a conservative Democrat who won the party’s nomination, argued that he will appeal more to general-election voters in a Republican-leaning district.

In the Seventh District, Representative Leonard Lance, a moderate Republican, will face former Obama administration official Tom Malinowski. And in the 11th District, where Rodney Frelinghuysen is retiring, the former Navy helicopter pilot and prosecutor Mikie Sherrill won the Democratic nomination against the former social worker Tamara Harris. State Assemblyman Jay Webber won the Republican nomination for the seat.