New Jersey Democratic Senator Robert Menendez has defied the White House by blocking the President's judicial pick for a spot on the Third Circuit U.S. Court of Appeals, with the Senator's motives coming into question from all sides.

President Obama had nominated U.S. Magistrate Patty Shwartz for the position, on a court just one step below the Supreme Court.  Senator Menendez, however, exercised his senatorial courtesy to block a nominee from his own state, as reported in Politico.

Divining the reason for the Senator's action is where it gets interesting, as Ms. Shwartz is highly regarded in legal circles:

Every lawyer in the world will tell you that she's extraordinarily qualified, a decent person and an excellent judge, and would be an asset to the circuit.

The New York Times also reports that:

... the nominee, Patty Shwartz, has been in a relationship for more than two decades with the head of the public corruption unit for New Jersey's federal prosecutor. And that unit investigated the senator during his 2006 election fight, an inquiry Mr. Menendez has long contended was politically motivated.

The investigation, which centered on a non-profit group that rented space from Menendez while Menendez helped the group obtain "millions of dollars in grants," was opened by then U.S. Attorney Chris Christie, but was finally closed a few months ago, with no charges filed.

According to the Newark Star-Ledger's Tom Moran, another bit of intrigue may also be in play:

The second rumor is that Menendez did this because Shwartz was the choice of fellow New Jersey Democratic Sen. Frank Lautenberg. The two men are bitter rivals...

Not to mention that New Jersey Democrats and Republican Governor Chris Christie are like oil and water.

Senator Menendez voted against the last debt ceiling increase not because he wanted to limit spending, but because "oil companies, billionaires and corporate jet owners" were not asked to "pay their fair share."

Menendez adamantly denies he has a "petty political vendetta" over the Shwartz nomination, and he issued some classic legal jargon in his own defense:

In the interview with Judge Shwartz, in my opinion, she misapplied the application of strict scrutiny versus rational basis review to the questions at hand...

...She did not express substantive knowledge as to the scope of the rights of corporations under the Constitution or jurisprudence on the constitutional limits of Executive Branch powers.

Whatever tortured logic Menendez comes up, the Moran column reports that White House officials are "furious" and "shocked."

Moran further notes that, whatever the reason, Menendez, who already had low approval numbers for a heavily Democratic state, has given his political opposition a "perfect chance to plant dark rumors about his motives." 

As former Democratic House Speaker Tip O'Neill liked to say, "all politics is local."