It muddies the waters by focusing on divisive issues like immigration enforcement and de-emphasizing the war, preventing what could be a unified left-and-right antiwar movement.
Plain anti-war protests could draw significant support across the political spectrum, so divisive issues are inserted as wedges. Same thing that happened in the 60's, when the anti-war movement went from a coat-and-tie affair to a laurel canyon one.
So Indivisible, which planned the protest, knew the US was going to attack Iran months in advance and plotted this protest to distract from it? What strategic masterminds! What opsec! The left always seemed so fractious and disorganized, but they were just wily, biding their time. But, why?
Seriously, I'm sure you're smart enough to know this is absurd. Just sit down and think about it a bit.
There will be no public rapprochement between the right and the left pretty much anywhere in the world.
They are fed by entirely different media machines.
If you like, its a coordination problem where the various groups no longer have the commons of a shared reality to coordinate through.
There is no anti-war movement on the right. The only time there is, is when a Right-winger is trying to win an election. Once said right winger inevitably starts a war, the pom poms come out.
If you think the No Kings movement is preventing a unified front against the war, you haven't been paying attention to the political discourse in the US since the rise of the Tea Party 15+ years ago.