The ACLU has been very active both politically and in litigation in opposing federal and state legislation that in various ways penalizes boycotting Israel. Commentators up and down the progressive left have been relying on the ACLU for the proposition that this legislation is a violation of First Amendment free speech rights.
For the record, the ACLU is misstating various Supreme Court holdings; as Eugene Volokh has explained, as a general rule there is no recognized right to engage in, as opposed to advocating, an economic boycott.
But let’s assume that the ACLU sincerely believes there is, or there should be, such a constitutional right. One would logically expect that ACLU to therefore be on the side of religious bakers, photographers, caterers, and so on, who choose to boycott same-sex weddings despite civil rights laws that require the contrary. In fact, the ACLU not only hasn’t supported the service providers, it has strongly supported government suppression of these boycotts.
But wait, some interlocutors have told me, there’s a difference between supporting antidiscrimination laws protecting Americans from discrimination, and laws protecting a foreign government from discrimination. There may be all sorts of ideological, moral, and practical differences; there are no constitutional differences. (And note that protecting same-sex weddings from discrimination is not quite the same thing as protecting homosexual individuals from discrimination.)
So from a constitutional perspective, either you support the right to boycott in the face of government attempts to protect a class from discrimination, or you don’t. The ACLU, however, wants to have its (same-sex wedding) cake and eat it too: boycotts against disfavored entities (Israel, or the military in FAIR v. Rumsfeld) are constitutionally protected, but boycotts contrary to laws it likes are not. It doesn’t work that way, and certainly won’t under the current Supreme Court. If any reporter that’s quoted the ACLU on the Israel legislation has asked how the ACLU justifies its hypocrisy on the issue of boycotts and the First Amendment, I haven’t seen it.