Ever since Elon Musk bought Twitter, changed the social media site’s name to X and altered its moderation policies, progressives have been hunting for a substitute. To judge how their search is going, consider a recent item from Politico’s Playbook, which notes that “a number of prominent commentators, experts and groups” are pledging to post on other platforms before X.

“The ‘X-last’ strategy,” says Playbook, “led by Indivisible and the Progressive Change Campaign Committee, is an effort to shift discourse from Elon Musk’s platform to Bluesky.”

Note that they’re not demanding that people stop posting to X. They’re just asking them to post a bit less. It’s certainly inventive, but a little wistful, as though they’re aware how unlikely this is to work. A recent Pew Research Center analysis found that many news influencers have Bluesky accounts (I’m one of them) but that, like me, two-thirds post irregularly. By contrast, more than 80 percent still post to X on most days. Engagement on Bluesky appears to have peaked in mid-November. It’s now down about 50 percent, and the decline shows no sign of leveling out. This is the tyranny of social media network effects. When a network grows, each new user makes it more valuable to every other user, enabling exponential growth. When the users start leaving, however, those network effects also hasten the decline. Nor is this process likely to be halted by organizing your pals and exhorting people to be better, or getting progressive writers to post to Bluesky before X. Yes, seeding platforms early with a small group of influential individuals can help it grow, as other users flock to be around them. But when that movement is organized by liberal groups, it’s most likely to appeal to folks who are very interested in progressive politics — which is to say, the other people who have already moved to Bluesky.

You can’t blame them for trying, I suppose. But wait, actually, I can. Because even if this works, moving progressives off X into Bluesky’s beautiful blue bubble isn’t a great idea for the movement. This effort isn’t just a doomed attempt to re-create the old Twitter. It’s likely to sap already-waning progressive influence and make the movement itself less politically effective.

Consider why progressive groups are so eager to hasten the demise of X and move their users to other platforms. One reason is simply that they are mad at Musk for supporting Donald Trump and allowing the alt-right to flourish on X. But another is that they are trying to duplicate what used to be an incredible platform for liberal influence. For roughly a decade, Twitter hosted what is lightheartedly called the “national conversation” on issues of the day, particularly social justice and public health. Twitter never had that many users, compared with Instagram or Facebook. But it had a big group of influential users — politicians, policymakers, journalists and academics, all of whom were engaged in a 24/7 conversation about politics and current events. That was a boon to progressives, who wielded outsize influence on the platform because they were early adopters who outnumbered the conservatives. They were also better organized and better networked, and had the sympathy of Twitter’s professional-class employees, who proved increasingly susceptible to liberals’ demands for tighter moderation policies on things such as using male pronouns to refer to a transgender woman.

Moderation suppressed conservative users and stories that hurt the left — most notoriously, the story about Hunter Biden’s laptop, which Twitter throttled as “disinformation” in the run-up to the 2020 election. Of course, progressive Twitter mobs also policed the discourse themselves, securing high-profile firings that made many people afraid to cross them.

Thus, that national conversation ended up skewed toward liberal views, creating the illusion that their ideas were more popular than they actually were. That’s a major reason that institutions went all-in on diversity, equity and inclusion initiatives, and why the 2020 Democratic primary field moved so far to the left that Kamala Harris was still struggling to backtrack four years later. All that changed when Musk bought Twitter.

It’s not surprising that progressives want to return to the good old days. But it’s not working, and I’m skeptical it ever will.

Because the Musk and Trump haters are the largest and most passionate group, the result is something of an echo chamber where it’s hard to get positive engagement unless you’re saying things progressives want to hear — and where the negative engagement on things they don’t want to hear can be intense.

All this is pretty off-putting for folks who aren’t already rather progressive, and that creates a threefold problem for the ones who dream of getting the old band back together. Most obviously, it makes it hard for the platform to build a large enough userbase for the company to become financially self-sustaining, or for liberals to amass the influence they wielded on old Twitter. There, they accumulated power by shaping the contours of a conversation that included a lot of non-progressives. On Bluesky, they’re mostly talking among themselves.

Megan McArdle is a Washington Post columnist.