The probe concerned Menendez's pursuit of federal funding for a New Jersey nonprofit that rented space in a building he owned. No charges were ever brought, and the five-year probe was ended in October.
Menendez's office dismissed the idea that his opposition to Shwartz was motivated by revenge, and aides said his concern about the nomination stemmed from Shwartz's qualifications on issues such as the Citizens United U.S. Supreme Court ruling. Democrats and Menendez oppose the ruling in which the high court declared corporations have the right to spend unlimited funds on elections as an expression of their free-speech rights.
Before Friday's announcement, White House spokesman Eric Schultz had said the White House hoped Menendez would reconsider his opposition to Shwartz's nomination but added, "We are regretful that the Senator's motives were questioned."
Menendez's aide said that despite the dustups over Shwartz and Cuba, he is still working with the Obama administration on key issues. For example, he was on the Spanish language television station Univision Jan. 8, spreading the word about a new rule proposed by the White House to allow certain undocumented immigrants to remain in America while applying for legal status. The rule is likely to be well-received by members of the Hispanic community, who may face years of separation from family while they apply for a green card.
Still, his opposition to Shwartz put him in a very public dispute with the White House.
"People are questioning whether he really did the right thing by putting this on people's radar," said Peter Woolley, director of Fairleigh Dickinson University's PublicMind Polling Institute.
"I think its hard not to make the connection between her and her boyfriend," Woolley said.
Menendez also bucked the White House on the deal reached in August to raise the debt ceiling by $2.1 trillion in two separate increases. Under the deal, the increase would be offset by an initial $917 billion in cuts over 10 years and another $1.2 trillion in automatic cuts over 10 years beginning in 2013 divided evenly between defense and nondefense spending. Those cuts were triggered when the super committee failed to hammer out a different deficit reduction package.
Menendez opposed the pact because it was offset with spending cuts that he argued would hurt the middle class.
"I cannot in good conscience support a plan where soldiers, seniors, students, and working families must endure trillions in cuts, while oil companies, billionaires, and corporate jet owners are not asked to pay their fair share," Menendez said in a statement at the time.
Another point of contention has been Cuba policy. In 2009, Menendez, who is of Cuban descent and passionate about the issue, blocked a $410 billion omnibus spending package because he disagreed with a provision to relax travel restrictions to the island. The New Jersey Senator also held up two other Obama administration nominees in order to win concessions from the White House on Cuba policy.
Eventually Menendez backed off after getting assurance from the Treasury Department that it would narrowly interpret the provision.
But Menendez was criticized for his opposition by senior White House officials, including then-Chief of Staff Rahm Emanuel, and rank-and-file Senators who raised the issue of whether Menendez should get to remain in the Democratic leadership.
His aides stressed that despite the tumult, the Cuba issue was worked out.
Former Sen. Scott Brown, R-Mass., candidate for U.S. Senate in New Hampshire, holds his hand over his heart during the singing of the national anthem as he waits to take the stage for his town hall campaign rally with Sen. John McCain at the Pinkerton Academy in Derry, N.H., on Monday, Aug. 18, 2014.