I snatched a bit of this article (behind a paywall) but it doesn't quote figures as a percentage of total lobbying but the numbers are huge. And because of the toxification of AIPAC as a brand they have diversified into lots of less well know, non-apartheid state branded groups (plus increased personal donations).

https://www.nytimes.com/interactive/2026/08/04/us/politics/aipac-israel-funds-spending.html

In less than five years, the American Israel Public Affairs Committee has become one of the biggest spenders in American elections, flooding the airwaves in congressional races across the country.

Since its first involvement in elections, the amount of money AIPAC-affiliated political action committees have spent on campaign advertising and outreach to voters has more than doubled, from $29.3 million to $67.2 million, with much of it spent in Democratic primaries.




also




In 2022, AIPAC created a super PAC that has spent more money on TV, radio and digital ads in federal elections over the past three election cycles than any other special interest group not linked to a political party, according to a Times analysis of data collected by AdImpact, a media tracking firm. AIPAC’s rapid growth in election spending, both through its super PAC and other new affiliated organizations, makes clear how significant the issue of Israel has become in American politics — but also how complicated.