By Michael Doyle and William Douglas, McClatchy Washington Bureau (TNS)

WASHINGTON — A federal grand jury on Wednesday indicted Sen. Robert Menendez of New Jersey, charging the senior Democrat on the Senate Foreign Relations Committee with trading political help for assorted benefits from an ambitious Florida eye doctor.

The ophthalmologist, Dr. Salomon Melgen, bestowed campaign contributions, plane rides, and gifts upon the 61-year-old Menendez over the course of their long relationship. Menendez, prosecutors say, reciprocated by trying to help Melgen’s various business and personal ventures.

“Government corruption, at any level of elected office, corrodes the public trust and weakens our democratic system,” said Assistant Attorney General Leslie R. Caldwell.

Menendez and Melgen, 61, of West Palm Beach, Fla., were indicted in the District of New Jersey for one count of conspiracy, one count of violating the travel act, eight counts of bribery, and three counts of honest services fraud.

Menendez also was charged with one count of making false statements.

In a news conference Wednesday night, Menendez declared his innocence and said he would be vindicated.

“I have always conducted myself in accordance with the law,” he said, adding that “this is not how my career is going to end.”

He issued a subsequent statement Wednesday night that he would temporarily step down from his role as ranking Democrat on the Senate Foreign Relations Committee.

“While there is no caucus rule that dictates that I do so,” Menendez said, “I believe it is in the best interests of the committee, my colleagues, and the Senate which is why I have chosen to do so.”

According to the indictment, Menendez between 2006 and 2013 accepted flights on Melgen’s private jet, as well as on a commercial and a chartered jet. He was also treated to numerous vacations at Melgen’s Caribbean villa in the Dominican Republic and to a three-night stay in 2010 at a swank Paris hotel, the indictment charges.

The Paris hotel suite cost $1,536.96 per night, plus tax and fees. Melgen covered it with his American Express Rewards points, according to the indictment.

During the same period, according to the indictment, Menendez repeatedly pressured federal government officials on Melgen’s behalf. The senator took Melgen’s side in a Medicare billing dispute, backed him in another dispute over a port security contract and assisted several women that the indictment described as “Melgen’s foreign girlfriends.”

All three of the women, from Brazil, the Dominican Republic, and the Ukraine, had worked as models, according to the 68-page indictment. For each, at Melgen’s request, Menendez directed his Senate staff to help with securing visas.

“Prosecutors at the Department of Justice don’t know the difference between friendship and corruption,” Menendez said.

His junior Democratic colleague from New Jersey, Sen. Cory Booker, said in a statement that he “won’t waver” in his “commitment to stand alongside” Menendez.

Melgen’s attorneys declined to comment Wednesday.

The prosecution itself, pursued by members of the Justice Department’s Public Integrity Section, could pose tricky legal questions about the fine line that sometimes separates honest friendship and politics-as-usual from quid-pro-quo trades.

By his own account, Menendez is a “quintessential American story,” as he grew up the son of Cuban immigrants in a Union City, N.J., tenement. According to his Senate biography, he “stood up to corruption” in Union City as mayor and later as a state legislator.

First elected to the House of Representatives in 1992, and to the Senate in 2006, Menendez has become a pivotal figure on Capitol Hill. His colleagues thought enough of his fundraising prowess to have him serve as Democratic Senatorial Campaign Committee head from 2009 to 2011.

He last won election in 2012, spending $16.2 million on his way to handily dispatching an underfunded Republican opponent.

Menendez has been a major critic of the Obama administration’s negotiations to stem Iran’s nuclear program and is co-sponsor of a bill to require congressional review of any nuclear deal.

His indictment also could impact the stalled nomination of Loretta Lynch as attorney general. The current vote count is close enough that Vice President Joe Biden could be called upon for a tie-breaking vote, if Menendez joins all other Democrats in voting for Lynch. Some Democratic aides said last week that Menendez may not vote on Lynch’s nomination to avoid the appearance of conflict of interest.

Menendez and Melgen have known each other for several decades, with Melgen delivering his initial $500 campaign contribution to the New Jersey politician in 1993. Since then, Melgen and his family members have repeatedly donated to Menendez’s campaign treasury, as well as those of various state and federal Democratic committees.

Ties between the two men have drawn scrutiny in recent years, as New Jersey Republicans in 2012 formally complained that Menendez had broken Senate rules by flying on Melgen’s private jet. In January 2013, Menendez used his own funds to reimburse Melgen $58,500 for travel expenses.

“Senator Menendez has traveled on Dr. Melgen’s plane on three occasions, all of which have been paid for and reported appropriately,” Menendez’s office said in a statement at the time.

But while the private flights and campaign contributions had previously become known, along with the bare facts of Melgen’s Medicare billing dispute, the indictment Wednesday offered many fresh details about political clout in action.

The dispute involved the Centers for Medicaid and Medicare Service’s conclusion that Melgen’s practice should repay the government $8,981,514.42 for overbilling on a certain drug.

Starting in 2009, the indictment recounts how Menendez personally advocated Melgen’s cause to everyone from the chairman of the Senate Health, Education, Labor and Pensions Committee to the secretary of the Department of Health and Human Services.

Menendez’s persistent advocacy extended for several years and coincided in 2012, with Melgen providing hundreds of thousands of dollars in campaign contributions to assist the New Jersey Democrat.

Menendez already has established a Robert Menendez Legal Expense Trust to help cover his already substantial legal fees. Through 2014, the fund had raised $784,250 and had spent most of it.

He is one of the least wealthy senators currently serving, with his most recent financial disclosure statement showing he is among the Senate’s relatively few non-millionaires.

(Lesley Clark of the Washington Bureau contributed.)

(c)2015 McClatchy Washington Bureau, Distributed by Tribune Content Agency, LLC

Photo: World Economic Forum / Benedikt von Loebell via Flickr