In Washington, sometimes what doesn’t happen is as significant as what does.

For example, every March for the past several decades, the American Israel Public Affairs Committee — the powerful pro-Israel lobby best known by its acronym, AIPAC — holds its annual convention in Washington, drawing thousands of supporters, lawmakers and top administration officials in a boisterous display of support for the Jewish state and the US-Israel relationship. In the lead-up to the convention, the lobby traditionally garners nearly unanimous support in Congress for some form of pro-Israel legislation so AIPAC can showcase its influence on both sides of the aisle.

In advance of this year’s gathering, AIPAC — which dutifully supports the right-wing government of Prime Minister Benjamin Netanyahu — wanted Congress to approve a measure that would expand existing prohibitions against anti-Israel boycotts by punishing anyone who blacklists products made in Israel’s West Bank settlements. It also sought broad bipartisan endorsements in the Senate for a letter to then-Secretary of State Rex Tillerson, backing his efforts to win European support to toughen the terms of the 2015 Iran nuclear deal.

But those efforts drew fire from J Street, a much smaller lobby with progressive views on Israel. According to Democratic congressional aides, the group lobbied lawmakers to oppose the anti-boycott measure, arguing it not only blurred the line between Israel proper and the occupied West Bank but stifled constitutionally protected free speech as well. J Street lobbyists also urged senators to shun the Iran letter, bringing Israeli security experts to Capitol Hill to warn that the Trump administration’s efforts to alter the nuclear deal were endangering both the agreement and Israeli security.