It's not like the Israelis haven't done this before and not paid any consequences for it. 2000: https://www.wrmea.org/000-june/despite-coverup-israel-caught... 2015 caught greasing politicians: https://www.wsj.com/articles/u-s-spy-net-on-israel-snares-co... 2011: https://www.nytimes.com/2011/09/08/us/08spy.html 2015: https://theintercept.com/2015/03/25/netanyahus-spying-denial... 2014: https://www.newsweek.com/israel…
Without support from the USA, it would not be possible for Israel to defend itself. Much of their spying on the USA is not to harm the USA, but to ensure the USA is still on their side. I don't think they want to hurt the USA, but I do think they would support an opponent of a politician that had been "heard" expressing a lack of interest in financial and military support for Israel.
Examples:
https://www.independent.co.uk/news/world/israel-accused-of-s...
https://www.military.com/defensetech/2013/12/24/report-israe...
I could be wrong! Maybe selling US secrets to china is to ensure the USA is still on their side? I'm not a politician; it's above my paygrade.
Somehow other US allies don't have these sorts of "hey let's spy on our friends" impulses. FWIIW the US just had an all-hands freak out over Russia spending a few grand on FB ads during the last presidential election; I'm pretty sure if it ever got out what the Israelis are doing out in the open to influence US elections (such as attempting to kick Israel critic politicians out of office), that would do even more harm to US-Israel relations than any single politician could.
I also think they can do just fine without US support. They have Jericho missiles capable of reaching LA. Technically this makes all US financial support of Israel illegal. I mean why would they risk all that needed support and build nukes capable of blowing up the US?