Do you, as a political party or government as a whole, abandon an ally you have all sorts of ties with because a sub-section of your voters don’t like that country anymore?

Given the, you know, genocide, the answer is "yes.*

but there’s no way they could have known that.

Yeah, it’s not like there was a whole mass movement saying exactly that.

The proper method is to start drawing lines with the ally and see if they cross them.

Which they did, every single time. Where are the consequences?

He did verbally state he was against what Israel was doing. He did float arms shipment cancellations to Israel. He did try to broker a peace deal. These were reasonable steps.

Ronald Reagan got the IDF to stop firing on Beirut after a 20 minute phone call. That’s a reasonable step; what Biden did was theater.