With AI risk getting significant media attention lately (FLI open letter, Eliezer's letter), I think it's plausible that the Overton window has expanded enough where a presidential candidate talking about it won't get immediately laughed off stage.
In addition, there seems to be increased positive sentiment around a global treaty to pause AI development within the rationalist/EA community.
It seems reasonable to me then that the rationalist/EA community should try to put forth a candidate for the US 2024 presidential election where one of their main platforms is mitigating existential AI risk.
I wouldn't expect them to succeed, but hopefully they can at least open the Overton window further to the point where at least other candidates engage with it a little and voters ask some questions.
Has there been any planning/thinking around this?
A few points.
With the same resources, it's probably easier and more effective to try to persuade candidates who are more successful.
From what I can tell, Harris has impressively low name recognition and is fairly unpopular with voters. That doesn't mean that party elites won't object to an outside group sponsoring a candidate who doesn't have their blessing.