Mr. Trump has become eager to restore his online presence and announced plans to launch his own platform. But even without the social-media tools that helped ignite his rapid political rise, Mr. Trump’s influence remains strong and in some ways has grown.

The ban has been a rallying point among the former president’s supporters. And while Mr. Trump’s poll ratings remain more negative than positive, public opinion about the former branding magnate and reality TV star has improved significantly since he was removed from social media after his supporters—echoing many of his false claims about election fraud—stormed the Capitol on Jan. 6, 2021, seeking to overturn his election loss. Facebook, now called Meta Platforms Inc., suspended his account on Jan. 7, and Twitter Inc. banned him on Jan. 8.

One year after the violent riot in the Capitol, roughly 52% of Americans said they had an unfavorable view of Mr. Trump compared with 43% who viewed him favorably, according to a FiveThirtyEight.com average of national polls. That 9-point gap compared with a nearly 20-point spread in Mr. Trump’s favorability rating a year earlier, according to the same polling average.