On Monday, 47 Republican senators led by Tom Cotton, R-Ark., released an " open letter" to Iran's leaders noting that any deal the regime signs with President Obama without the approval of Congress could be revoked by a future president or changed by Congress. The White House went into a tizzy trying to portray the move as somehow "unprecedented" — a view that has found a friendly audience with the media.

Vice President Joe Biden claimed the letter "ignores two centuries of precedent and threatens to undermine the ability of any future American president, whether democrat or republican, to negotiate with other nations on behalf of the United States." The New York Daily News featured an editorial blasting the letter on its front page, with photos of the senators and the bold-faced headline "TRAITORS." A more muted NBC roundup called the move "extraordinary — if not unprecedented." In reality, whatever one's view of the letter, to call it "unprecedented" is to ignore history. The reality is that on many occasions, Democrats have reached out to foreign leaders to undermine the foreign policy of a sitting Republican president.

Here are just five examples.

1. That time "liberal lion" Ted Kennedy proposed a secret alliance with the Soviet Union to defeat President Ronald Reagan

A 1983 KGB memo uncovered after the fall of the Soviet Union described a meeting between former KGB officials and former Democratic Sen. John Tunney (Sen. Kennedy's confidant) in Moscow. Tunney asked the KGB to convey a message to Yuri Andropov, the Soviet leader, proposing a campaign in which Kennedy would visit Moscow to offer talking points to Andropov and Soviet officials on how to attack Reagan's policies to U.S. audiences. According to the memo, Kennedy, through the intermediary, offered to help facilitate a media tour in a proposed visit by Andropov to the U.S. Kennedy's hope, as conveyed by the letter, was to hurt Reagan politically on foreign policy at a time when the economic recovery was working in his favor.

2. "Dear Comandante"

In 1984, 10 Democratic lawmakers — including the then majority leader and House Intelligence Committee chairman – sent a letter to Nicaraguan Communist leader Daniel Ortega known as the "Dear Comandante" letter. In it, the lawmakers criticized Reagan's policy toward Nicaragua and whitewashed the record of violence by the Sandinista communists.

3. Pelosi visited Syrian ruler Bashar Assad

In 2007, newly elected House Speaker Nancy Pelosi visited the Syrian dictator Bashar Assad. As the Associated Press reported at the time, "The meeting was an attempt to push the Bush administration to open a direct dialogue with Syria, a step that the White House has rejected."

4. Democrats visited Iraq to attack Bush's policy

As Stephen Hayes recounts: "In September 2002, David Bonior, the second-ranking Democrat in the House of Representatives, flew to Baghdad in an attempt to undermine George W. Bush's case for war in Iraq on a trip paid for by Saddam Hussein's regime. Bonior, accompanied by Reps. Jim McDermott and Mike Thompson, actively propagandized for the Iraqi regime. McDermott, asked whether he found it acceptable to be used by the Iraqi regime, said he hoped the trip would end the suffering of children. 'We don't mind being used,' he said."

5. Jimmy Carter tried to sabotage George H.W. Bush at the U.N.

On Nov. 20, 1990, as President George H.W. Bush gathered support to oppose Iraq after its invasion of Kuwait, the former Democratic President Jimmy Carter wrote a letter to nations who were in the U.N. Security Council trying to kill the administration's efforts. As Douglas Brinkley explained, Carter's letter was an attempt "to thwart the Bush administration's request for U.N. authorization of hostilities against Iraq. President Bush's criterion for proceeding with a war was the exhaustion of 'good faith talks,' and Carter placed his interpretation of that standard above the administration's."