Democrats have been quick to issue harsh responses to Israeli Prime Minister Benjamin Netanyahu's speech to Congress on Iran. An anonymous White House official gave a pretty stern, if anonymous, quote to CNN's Jake Tapper, telling him that the speech offered "literally, not one new idea," and was "all rhetoric, no action."

Sr. administration official: "Literally, not one new idea; not one single concrete alternative; all rhetoric, no action." — Jake Tapper (@jaketapper) March 3, 2015

An anonymous senior White House official also slammed the speech in comments to the Jerusalem Post, saying that "simply demanding that Iran capitulate is not a plan," and that the logic of Netanyahu's remarks was regime change in Iran:

Senior administration official tells me: "Simply demanding that #Iran completely capitulate is not a plan." #NetanyahuSpeech #Israel — Michael Wilner (@mawilner) March 3, 2015

House Minority Leader Nancy Pelosi also immediately panned the substance of Netanyahu's remarks.

Within minutes of the end of the speech, she issued a statement saying that she had been "near tears throughout the Prime Minister's speech — saddened by the insult to the intelligence of the United States as part of the P5 +1 nations [leading Iran talks], and saddened by the condescension toward our knowledge of the threat posed by Iran and our broader commitment to preventing nuclear proliferation."

Why Democrats are so angry about Netanyahu's speech

Democrats have been furious about Netanyahu addressing Congress ever since the speech was announced in January. They perceive Netanyahu as not only trying to undermine President Obama's efforts to reach a nuclear deal with Iran, but also Obama's authority over US foreign policy.

Part of the problem is that Netanyahu went behind the White House's back to set up the speech. House Majority Leader John Boehner invited Netanyahu to address Congress without consulting or even notifying the White House about the invitation. The Israelis and the Republican leadership intentionally kept the White House out of the loop: Boehner said they wanted to make sure that there was "no interference" from the administration.

Although Boehner's office did notify the White House before issuing a "formal invitation" to Netanyahu, by that point the deal was done.

The speech was a major breach of protocol for both Israel and the Republican party. It was a breach of diplomatic protocol for Israel's leadership to work directly with an opposition party in that way. And it was a breach of political protocol for the Republicans to go behind the president's back to work directly with a foreign leader, because the president is supposed to be the US's sole organ in foreign affairs.

Both breaches were particularly egregious in this case, because they were intended to directly undermine Obama's ongoing diplomatic efforts on Iran.

That's why at least 55 Democrats announced plans to boycott the speech before it happened — and why the White House and the Democratic leadership have been so quick to denounce it now.