WASHINGTON -- Rep. Chris Smith, who hasn't received less than 60 percent of the vote in his last 17 elections, has just been added to the House Democrats' list of 2018 targets.

Thursday's announcement by the Democratic Congressional Campaign Committee means that the party is now focusing on every Republican-held seat in New Jersey.

It's also a sign of how Democrats hope that President Donald Trump's historic unpopularity -- along with an angry electorate and the fact that the party controlling the White House traditionally loses congressional seats in off-year elections -- will carry even safe Republicans such as Smith, R-4th Dist., into retirement.

"Democrats are firmly on offense for a variety of reasons, including incredible candidate recruitment, record-breaking fundraising, a historically unpopular Republican agenda, and extensive district level polling showing Democrats already beating or in close competition with their opponents," said the DCCC's chairman, Rep. Ben Ray Lujan, D-N.M.

While Trump's favorable ratings have ticked up, he still remains in negative territory. In a Quinnipiac University poll released Wednesday, 55 percent of U.S. voters disapproved of his perfromance in office, with just 40 percent approving.

In all, the DCCC added seven Republican-held districts to its target list, which already includes Reps. Tom MacArthur, R-3rd Dist., and Leonard Lance, R-7th Dist.; as well as the seats being vacated by retiring Reps. Frank LoBiondo, R-2nd Dist., and Rodney Frelinghuysen, R-11th Dist.

"Democrats have a proven record of overpromising and underdelivering," said Chris Martin, a spokesman for the National Republican Congressional Committee. "It's not surprising that they've been reduced to adding names to a wish list."

Smith, the longest-serving member of the New Jersey delegation, is considered a safe bet for re-election by two Washington-based publications that track congressional races, the Cook Political Report and Inside Elections.

"Voters trust Chris and consistently show their support for his record of legislative leadership and service to constituents," Smith spokeswoman Mary McDermott Noonan said. "He generally carries his district with 64 percent-plus, garnering a 100,000-vote margin in the last election."

He also had a large cash advantage over the two Democrats seeking to oust him, raising $307,634 through Dec. 31 and entering January with $392,450 in the bank.

Former Asbury Park Councilman Jim Keady, who memorably was told to "sit down and shut up" by then-Gov. Chris Christie, raised $145,488 with $61,019 to spend. Josh Welle brought in $172,813, contributed $8,430 of his own money, and had $133,119 cash on hand.

"We welcome the DCCC's support to flip the 4th District," Keady said. "It's long overdue that we send Congressman Smith into retirement."

Welle immediately sent out a fundraising email touting the DCCC's action.

"The 4th District made it onto the DCCC's radar because we need a congressman who will fight for a tax plan that doesn't devastate New Jersey and drive home values down, a congressman who will protect our beaches and environment from offshore oil drilling, a congressman who will work for affordable and accessible health care," Welle said.

Smith bucked his party on two high-profile votes last year.

He opposed the House Republican health care bill and voted against the GOP tax plan that gutted the federal deduction for state and local taxes. He also has joined the rest of the congressional delegation in opposing Trump's proposal to open the Jersey Shore to offshore oil drilling.

Only four House Republicans have supported Trump less than Smith has, according to Nate Silver's fivethirtyeight.com

Still, Smith is a Republican in a state that gave Trump a 61 percent disapproval rating, with just 34 percent approving, in a recent Gallup poll. Residents of only eight other states thought less of Trump than those living in New Jersey, according to the poll.

The Cook Political Report, meanwhile, changed its rating on the LoBiondo district Thursday and now makes state Sen. Jeff Van Drew, D-Cape May, a slight favorite to win in November.

"Van Drew looks almost as imposing as an incumbent," said David Wasserman, Cook's House race editor.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.