Lots of politicians have chosen to make Twitter their main method of communication. I am able to speak to my representatives via Twitter quite easily while they ignore my emails. They can choose (if they wish) to block me on Twitter and limit my ability to communicate with them or see important information they post there and not elsewhere. Either it’s a utility or our politicians need to be held to stricter rules re communication with their constituents.
If politicians choose to use Twitter, but could just as easily choose communication on the web by other means (like email, or another platform) then that makes Twitter merely convenient, not a "de facto utility".
Modern political campaigns are fought and won on social media. Politicians do not choose to use them, they have to use them to have a chance to get their message across.
> Modern political campaigns are fought and won on social media.
For the current definition of "modern".
In the 1800s then-modern political campaigns were fought and won in newspapers and pamphlets.
Pre-WW2 then-modern political campaigns were fought and won on the radio.
Post-WW2 then-modern political campaigns were fought and won on television.
None of those were treated as public utilities AFAICT, so I'm not why the medium of communication now suddenly makes a difference (Marshal McLuhan notwithstanding).
Trump didn't win because he personally had social media accounts from which he spread his message - canvassing by his followers (until they kept going Nazi and getting banned) were what was effective. Trump's own social media use has been a net negative for him, he mostly just rants and shitposts. If he'd been banned from Twitter earlier, he might have gotten more accomplished.
Also, coverage of Trump by the mainstream media was likely far more effective than social media at getting him elected. If nothing else, it provided the material that got spread across social media.
Obama's victory was due in large part to social media as well, but not due to Obama's personal accounts.
Trump utilized newspapers, TV news networks, rallies, and word of mouth as well. He's banned from twitter right now but still tops the poll of who would win the next election