In these cases, progressives lauded these boycotters as champions of equality. So why do national lawmakers — including supposedly progressive Democrats — want to make an exception for those who support equal rights for Palestinians?

When the cause is just, boycott has shown itself to be an effective method of shining light on human rights abuses and the flouting of international law. That is why the Israeli government and its supporters are so determined to silence those who support B.D.S.

Pro-Israel groups have for years attempted to demonize supporters of B.D.S. — trust me, I know. I am currently in the middle of a 63-date tour of the United States and Canada. Audiences of tens of thousands are coming together at our “Us + Them” shows, which embrace love, compassion, cooperation and coexistence and encourage resistance to authoritarianism and proto-fascism. These appearances have been greeted by a few sporadic protests by right-wing supporters of Israel.

These protests would be of no consequence, if they did not occasionally have truly negative consequences. For instance, the city of Miami Beach prevented a group of school children from appearing onstage with me after pressure from the Greater Miami Jewish Federation. I understand that city officials have a democratic right to disagree with my opinions, but I was shocked that they were willing to take it out on kids.

These attacks are routine and relatively minor. But the Israel Anti-Boycott Act is serious “lawfare.” Officials in Nassau County in Long Island are threatening to take legal action to shut down two shows I have scheduled there next week, using a local anti-B.D.S. law passed in 2016. If the Nassau County attorney proceeds against the operators of the Nassau Coliseum, we will have our day in court and argue on behalf of all those who believe in universal human rights and the First Amendment.

Polls show that nearly half of all Americans, and a majority of Democrats, would support sanctions against Israel because of its construction of illegal settlements on occupied Palestinian land. Indeed, more and more churches, student groups, artists, academics and labor organizations are backing the tactics of boycott and divestment as a means to pressure Israel to end its abuses of Palestinians. If passed, the Israel Anti-Boycott Act could put them all, from archbishops to altar boys, artists to artisans, at risk of arrest on felony charges.