Israel's Ambassador to the UN Danny Danon tore into Sen. Bernie Sanders during his speech at the pro-Israel lobby group AIPAC Sunday morning, calling the 2020 front-runner an "ignorant fool” and “a liar” and telling the audience, “We don’t want Sanders in Israel."

Why it matters: AIPAC, which has faced increasing difficulty in recent years maintaining American bipartisan relations with Israel, was hoping to avoid partisan politics at this year's conference. Danon’s remarks are not going to make this any easier.

The backdrop: Sanders sparked a controversy last week when he announced he will boycott the AIPAC conference because it provides a platform for what he called anti-Palestinian bigotry.