Great article. I'd add a lesser known but still important liberal Zionist, Matt Duss, who comes around to, as the "progressive position," support for boycott of the settlements, but not of Israel itself.
Duss's article is important because of its target (progressives), but more so because he actually lays out the groundwork well for boycotting Israel as a whole, even while smearing those who actually practice it. He says:
With Denmark’s biggest bank, Danske Bank, announcing earlier this week that it would no longer do business with Israel’s biggest bank, Bank Hapoalim, over the latter’s financing of settlements, those warnings are already coming to pass. Like the European Union’s announcement last summer of new guidelines prohibiting funding of Israeli organizations located in the occupied territories, these represent long-overdue steps to exact costs for an occupation that has continued for far too long. The aggressiveness of the debate—which is pretty pitched even on its best days—will only increase as the pressure increases. I think a responsible progressive position—which balances values with what is practically achievable—is one that marshals those pressures toward an end to the occupation and the creation of a Palestinian state in its place, alongside Israel.
This is all absolutely correct, but the point is that the pressures is to "exact costs for the occupation." This is done by pressuring Israel, the decision maker, not by pressuring the settlements themselves (i.e. the decision). This is the way pretty much all boycotts work. When activists boycotted Arizona because of its racist immigration laws, they did not boycott the police enforcing the laws, they boycotted the entire state. When farmworkers picking tomatos pressured Yum Brands (Taco Bell) for decent wages, they did not ask people to order their taco supremes with no tomatos, they called on people to boycott Taco Bell entirely. In every case, the target is the decision maker (in this case, Israel), and the method is economic and moral pressure across all their activities.
Now that boycotts against the settlements have basically gained acceptance in much of the chattering class, it is important to explain why such a limited boycott does not actually put pressure on Israel to acheive a breakthrough.