The issue is more it being approved at lower levels, but CEO Jack Dorsey directly killing it: an example of bias at the very top.
Any ad that directly mentions the opposing candidate, no matter how polite, is an attack ad. And there is no guidance from ANY regulatory authority that I can see, that bans, discourages, or even regulates them.
It still isn't an example of bias. It's just an example of Twitter not having clear internal policies and coordination for dealing with sensitive issues.
Which, frankly, has been an issue that plagues them on both sides of the political divide.
Any ad that directly mentions the opposing candidate, no matter how polite, is an attack ad. And there is no guidance from ANY regulatory authority that I can see, that bans, discourages, or even regulates them.