Dueling accusations are flying in South Jersey over a campaign mailer for the 3rd district U.S. House race.

State Democrats are accusing their Republican counterparts of distributing a "racist" ad targeting Democratic challenger Andy Kim, a Korean American. Kim is running against two-term Republican incumbent Tom MacArthur.

The ad features a photo of several whole fish on ice with the caption "There's something Real Fishy about Andy Kim."

"Real Fishy" and "Andy Kim" are spelled out in a type font a Democratic spokeswoman said is called "Chop Suey," and is often associated with Chinese food stores or Asian films.

"The GOP's decision to show images of raw fish and to use this particular red block font, which is actually called 'Chop Suey' and has long been used to visually convey Asian heritage, makes it abundantly clear what this mailer is -- a shameful racist attack on a qualified and capable public servant," said Caitlin Mota, a Democratic party spokeswoman.

The state GOP dismissed the Democrat's criticism.

"This is an ugly attempt to change a bad news cycle for Andy Kim," said Harrison Neeley, a GOP spokesman. "Let's not forget that Tom MacArthur has two Korean children."

A request to MacArthur for comment Wednesday was not immediately returned.

MacArthur has criticized Kim for being a liberal Democrat and for taking campaign contributions from U.S. House Democratic leader Nancy Pelosi.

A previous MacArthur ad ended with a phrase: "Kim, not one of us."

"This kind of divisive rhetoric is exactly what voters hate about Washington politicians," said Forrest Rilling, a Kim spokesman.

MacArthur "faces a significant challenge to keep his seat," according to a Monmouth University Poll that shows he's in a virtual tie with Democrat Andy Kim in New Jersey's 3rd Congressional District race.

The Monmouth University Poll gave Republican MacArthur a 1-point lead over Kim among potential voters, defined as those who have voted at least once since 2010 or have newly registered. MacArthur's 41 percent to 40 percent advantage is well within the survey's margin of error of 4.9 percentage points.

Kim had more money to spend entering July, $1.7 million to $1 million, Federal Election Commission filings show.

A majority of voters, 57 percent, said they viewed the race as a referendum on Donald Trump, including 66 percent of those who oppose the president and 60 percent who support him.

MacArthur has backed Trump more often than any other member of the New Jersey congressional delegation, according to Nate Silver's FiveThirtyEight.

Staff writer Jonathan D. Salant contributed to this report.

Bill Duhart may be reached at bduhart@njadvancemedia.com. Follow him on Twitter @bduhart. Find NJ.com on Facebook. Have a tip? Tell us. nj.com/tips