TRENTON -- Gov. Chris Christie's approval rating with New Jersey voters has reached a record low, a new poll finds -- worse, even, than the state's Democratic U.S. Sen. Robert Menendez, who is currently under criminal indictment on federal corruption and bribery charges.

A new Rutgers Eagleton survey released Thursday found the governor's approval has dipped to 26 percent, a drop of three percentage points since quitting the presidential race in February.

Meanwhile, his unfavorability rating has climbed to the highest point since first taking office in 2010, 64 percent.

"Negativity toward Christie continues to grow, but not entirely because of his support for GOP front-runner Donald Trump or his own involvement with the 2016 election cycle," said Ashley Koning, assistant director of the Eagleton Center for Public Interest Polling at Rutgers University.

Just 3 percent of his detractors mentioned something about his support for Donald Trump as a reason for their unfavorable rating, while only another 3 percent about Christie's role in the 2016 presidential election more generally.

"Christie's unpopularity stems from the same longstanding reasons that voters have cited in both their praise and condemnation of him throughout his tenure - reasons that disenchanted voters emphasize now more than ever two months after Christie's return to governing full time," Koning said.

The Rutgers poll found both Christie supporters and detractors pointed to the governor's character, his overall job as governor, and their perception of his honesty as informing their opinions.

Among those favorably inclined toward the governor, 35 percent like him because of "the overall job he is doing," 16 percent mention something about him being "honest and trustworthy," 13 percent point to his "character and attitude," and 11 percent reference his "policy decisions."

Among those unfavorable toward him, 15 percent point to his "character, personality, or attitude" as the main reason behind their negative rating. Another 7 percent specifically say something about his "confrontational, bully-like" persona.

An additional 15 percent cite Christie's "overall job as governor and governing style." Fourteen percent say he is "dishonest and untrustworthy."

The governor is still well liked by a majority of Garden State Republican voters, but has seen declines with them, too. Fifty-six percent of GOP voters have a favorable impression, while 34 percent have an unfavorable one.

That represents a seven point dip in favorability since Christie's endorsement of Trump.

Independent voters and Democrats, however, have largely turned against him, with 63 percent of independents and 87 percent of Democrats holding unfavorable views.

The poll also found Menendez, who is less well-known than the governor, fares a bit better with voters, despite his legal woes.

Twenty-nine percent of Garden State voters have a favorable view of the senior Democratic senator, while 32 percent hold an unfavorable view of him. Most - 39 percent - had "no opinion."

Voters were most positive toward U.S. Sen. Cory Booker. Forty-eight percent are favorable, while 23 percent are unfavorable, and another 30 percent have no opinion.

Sixty-four percent of Democrats, 47 percent of independents, and 26 percent of Republicans like the Democratic junior U.S. senator.

The Rutgers poll surveyed polled 738 registered voters using both landlines and cell phones from April 1 to 8, 2016, with a margin of error of 4 percentage points.

Claude Brodesser-Akner may be reached at cbrodesser@njadvancemedia.com. Follow him on Twitter @ClaudeBrodesser. Find NJ.com Politics on Facebook.