“It is sometimes said that the United States Senate is a rich man’s club,” Rep. Robert Andrews (D), the 11th-hour primary challenger to New Jersey Sen. Frank Lautenberg (D), said at his official campaign announcement on Monday.

Although Andrews was attempting to make a point about the “richness” of love he felt from the friends and family that had gathered in Trenton to support him, the Congressman’s initial point still stands.

Senate seats in New Jersey can be among the most expensive Congressional seats in the country. Eight years ago, now-Gov. Jon Corzine (D) spent $63 million, mostly from his own pocket, to secure the Senate seat of a then-retiring Lautenberg. Two years ago, Sen. Bob Menendez (D) and state Sen. Tom Kean Jr. (R) combined to spend more than $21 million in the battle over Corzine’s open seat.

So in the current race, Lautenberg’s deep pockets — as well as his well-oiled state and nationwide fundraising machine — give him a huge initial advantage over both Andrews and the latest Republican frontrunner to enter the Senate contest, former Rep. Dick Zimmer.

Just hours after Andrews kicked off his campaign Monday, four Democratic Senators from around the country joined Corzine to host a $500-a-head fundraising event for Lautenberg at the New Jersey Performing Arts Center in Newark.

The money raised from that event will be part of the more than $1 million in fundraising commitments that Lautenberg has secured since Andrews first made it known two weeks ago that he would challenge the sitting Senator, according to a Lautenberg source.

Lautenberg already had more than $4 million in his campaign coffers back when this race was expected to be little more than a coronation, and his personal wealth is estimated to be somewhere around $40 million.

But even though it’s highly unlikely that Andrews or Zimmer will be able to come close to outspending Lautenberg in this race, the support from the Democratic establishment for the incumbents is still pouring in.

In two weeks, Senate Majority Leader Harry Reid (D-Nev.), Democratic Senatorial Campaign Committee Chairman Charles Schumer (N.Y.) and the rest of the Garden State Democratic delegation are scheduled to hold another major fundraiser for Lautenberg in Washington, D.C.

Meanwhile, according to his April 15 Federal Election Commission report, Andrews raised $181,000 in the first quarter of 2008 and had $2.2 million cash on hand. Over the course of the entire cycle he had raised less than $1.4 million. But at least Andrews has that.

Zimmer had been working at a D.C. lobbying firm until late last week when he was tapped by state party leaders to replace businessman Andy Unanue (R) on the ballot. He is running against state Sen. Joe Pennacchio and college professor Murray Sabrin in the Republican primary.

Zimmer’s selection by state party leaders seems to be a shift in strategy for trying to steal the Senate seat. Unanue and the woman he replaced in the race, real estate developer Anne Evans Estabrook, were both personally wealthy, which was considered necessary in order to compete against New Jersey Democrats in a cycle in which there is little national GOP money to go around.

With Zimmer, a former three-term Member who lost the 1996 Senate race, Republicans don’t have to spend money introducing him to voters and can bank on his established name recognition. Zimmer last ran for office in 2000 when he lost a comeback bid to Rep. Rush Holt (D). But in that campaign, Zimmer raised a respectable $2 million, and in his losing 1996 Senate campaign he raised more than $8 million.

“He’s been a successful fundraiser in the past. He is very well known to the political establishment in New Jersey. He’s a known commodity to the prominent Republican fundraisers in the state,” said Mark Campbell, a national GOP consultant.

And rather than suffering through the growing pains that come with a first-time candidate, GOP leaders can at least rest assured that “Dick Zimmer is an experienced political force in the state and should be able to run a mistake-free campaign,” Campbell said.

Campbell pointed out that gobs of money doesn’t always equal massive amounts of votes.

In Corzine’s 2000 campaign, in which he spent 10 times as much money as then-Rep. Bob Franks, the Republican nominee, his winning margin was a mere 3 points.

Besides, Zimmer’s campaign is clearly expecting a bloody primary fight between Andrew and Lautenberg. Republicans hope that will leave the eventual nominee hobbled for the general election and that the animosity born from that fight will only discourage Democrats and motivate Republicans, both in New Jersey and around the country.

“If we can keep this close, we expect there will be national money,” said Ken Kurson, a spokesman for Zimmer’s campaign.