WASHINGTON -- In the last week, two polls put U.S. Sen. Robert Menendez's lead within their margins of error and a Washington publication that tracks Senate races made him just a slight favorite to be re-elected.

Time to call in the cavalry. But don't say the Democrats are in panic mode.

"When you get to a point where the professionals on the team start deciding they need to pull out all the stops to win, everybody calls that a panic," Democratic consultant Glenn Totten said.

"They're going to put their shoulder to the wheel and work very hard to make sure that Bob Menendez wins the race, but they have some urgency now. That's a long way from panic."

With Democrats already a long shot to pick up the two Republican-held seats they need to regain control of the Senate, the last thing the party can afford is a loss in a Democratic-leaning state where 62 percent of likely voters disapprove of President Donald Trump's performance in office.

Instead, the race between Menendez, D-N.J., and former Celgene Corp. executive Bob Hugin is close enough that the Democratic Senatorial Committee is spending another $400,000.

The committee made a similar $500,000 expenditure in August to back Menendez, Federal Election Commission reports show.

DSCC spokesman David Bergstein said Hugin, who put $15.5 million of his own money into the contest though June 30, was trying to buy a Senate seat.

"It won't work and Senator Menendez will continue fighting for New Jersey just as he has throughout his entire career in public service," Bergstein said.

The money will be spent in the New York City and Philadelphia media markets and coordinated with the Menendez campaign, meaning the party will be charged the lower ad rate for candidates rather than the higher rate for outside groups.

"National Democrats are finally recognizing what has been clear for months --disgraced Senator Bob Menendez is toxic among New Jersey voters and his seat is in serious jeopardy," said Bob Salera, a spokesman for the National Republican Senatorial Committee.

Those national Democrats said they can't envision a scenario in which Menendez loses.

"He is a very skilled politician who knows the state very well," said Jim Manley, a former aide to then-Senate Majority Leader Harry Reid, D-Nev. "And probably most importantly, he knows how to play hardball like few others."

Nate Silver's FiveThirtyEight, in fact, gave Menendez a nine in 10 chance of winning re-election.

Menendez now leads by 6.3 percentage points in the Real Clear Average of polls while Hugin has never been ahead in any survey. The most recent poll of the race, by Quinnipiac University, put him ahead by 11 points among likely voters.

"When they're in the voting booth and talking to their families and friends, they're going to vote for Democrats in New Jersey," said Israel Klein, a West Orange native and former aide to now-Senate Democratic Leader Chuck Schumer of New York, who now runs his own lobbying firm in Washington.

Menendez also could receive a boost from the state's competitive House races that are taking place in Republican-held districts. In four of the five GOP-held districts, including two that have been in Republican hands for more than two decades, the Democratic candidate is given no worse than a 50-50 chance of prevailing in November.

"There's a very strong undercurrent of support for Democratic candidates lower on the ballot," Klein said.

At the same time, Menendez's 6-point lead in the most recent Fairleigh Dickinson University likely voter poll was within the margin of error. Before then, a Stockton University survey gave him only a 2-point advantage among likely voters, also with the margin of error.

And the Cook Political Report lowered its rating on Menendez and said he now was just a slight favorite to be re-elected, putting him in the same category as West Virginia Democratic Sen. Joe Manchin rather than either of the Democratic senators representing New Jersey's neighbors, Kirsten Gillibrand of New York and Bob Casey of Pennsylvania.

Unlike his neighbors, Menendez faces a wealthy opponent and has a high unfavorable ratings. He was viewed unfavorably by 53 percent and favorably by 34 percent in the Quinnipiac poll.

Hugin's ads have hit Menendez on his indictment for corruption charges. His trial ended up with a hung jury, and after a judge acquitted him of some counts, federal prosecutors declined to try him again. The Senate, however, severely admonished him for intervening with federal agencies on behalf of a friend an campaign donor, Dr. Salomon Melgen.

"The fundamentals of the race and the political environment are the same," said Nathan Gonzales, editor and publisher of Inside Elections, another Washington-based publication that tracks Senate races and rates Menendez as a stronger favorite for re-election.

"He's a Democrat running in a Democratic state in a Democratic year. I'm not sure there are enough voters who don't like him who will help maintain the Republican majority in the United States Senate."

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