Yesterday, Twitter announced that it would not carry any political ads (broadly defined to include issue ads as in the Honest Ads Act/SHIELD Act) on its platform.  Under current law, this is perfectly permissible.  It contrasts with the approach taken by Facebook, which announced recently that it would not decide truth and falsity in political ads.  Democrats and the mainstream media were quick to praise the decision:

Several 2020 Democratic presidential candidates responded to the news by calling on Facebook to do the same. “I applaud Twitter’s decision to ban political ads. It’s the rare triumph of the public good over the bottom line,” Andrew Yang wrote on Twitter. “I hope Facebook follows suit or at least verifies and stands by the accuracy of political ads on its platform.” Montana Gov. Steve Bullock also praised the move on Twitter, adding, “Your turn, Facebook.” (Both are currently promoting their campaigns through Facebook ads.) And don’t forget about the nudge from Hillary Clinton: “This is the right thing to do for democracy in America and all over the world,” she posted. “What say you, @Facebook?”

This decision is so popular with Democrats because of their desire for more regulation of political speech and their frequent handwringing over "dark money." Twitter CEO Jack Dorsey framed the decision in precisely these terms:

In addition, we need more forward-looking political ad regulation (very difficult to do). Ad transparency requirements are progress, but not enough. The internet provides entirely new capabilities, and regulators need to think past the present day to ensure a level playing field.

— jack 🌍🌏🌎 (@jack) October 30, 2019

A final note. This isn’t about free expression. This is about paying for reach. And paying to increase the reach of political speech has significant ramifications that today’s democratic infrastructure may not be prepared to handle. It’s worth stepping back in order to address.

— jack 🌍🌏🌎 (@jack) October 30, 2019

Twitter is, of course, a private company and allowed to have this policy, and the different approaches taken by Twitter and Facebook are examples of the free market at work, as noted by the Competitive Enterprise Institute's Jessica Melugin:

The advantages of running this experiment in the marketplace, instead of the government regulatory realm, are manifold. When private companies make decisions with their private property, they have skin in the game to create maximum incentives for success. Not so when regulators and legislators politicize these decisions. And unlike a static regulatory regime, a dynamic marketplace allows companies to more quickly reverse, recalibrate, or ramp up their approach based on feedback from consumers and clients. Lastly, experiments on the economic frontier allow for the innovation and adjustment that heavy-handed regulations often stifle.

Mr. Dorsey acknowledged yet brushed aside a concern that this move will benefit incumbents, yet that is precisely what it will do.  President Trump, the main 2020 Democratic contenders, the NRA, and the Sierra Club have an enormous number of followers and do not need paid ads to share their message. But a longshot challenger to an incumbent, a small issue-focused organization, a local government candidate - those are the people and organizations who need paid ads to be able to disseminate their messages:

Twitter’s new policy could seriously harm some smaller organizations and politicians who are attempting to etch out a space in a crowded digital ecosphere. Nonprofits attempting to reach larger audiences and challengers to incumbent officeholders are likely to be detrimentally affected.

“If you’re a challenger, advertising allows you to make up that difference,” Matt Shupe, a Republican political strategist, told reporters. “It’s very hard to organically grow an audience for a state assemblyman campaign.” Trump’s reelection campaign also criticized the move.

As usual, Senator Ted Cruz summarizes the relevant issues:

First, if banning political ads – from candidates, groups, or individual citizens – becomes the norm, that only stands to benefit two groups: incumbent politicians and the mainstream media. . . .

Second, Twitter’s ban only further empowers Silicon Valley billionaires, who already have a stronghold on defining what is truthful or acceptable speech, to now define what is and what is not “political.” It’s up to them to determine where to draw the line – and they won’t stop here. Banning ads is just the beginning. . . .

What the left defines as "false" is anything that they disagree with.

And, critically, it is only the left that is calling for censorship. I don't want social media to silence Bernie Sanders or Elizabeth Warren. I think their socialist agenda is nonsense. But, I am perfectly happy to engage them on substance to demonstrate that socialism has proven to be an abject failure and that the American free enterprise system has been the greatest enemy that poverty has ever seen.

While all tech companies have shown anti-conservative bias and Twitter is certainly allowed to have a policy against policy and issue ads, Facebook's approach is much more in conformity with American values of open discussion and the responsibility of the citizen to evaluate the information and candidates to cast an informed, considered vote.