I could be wrong but I think it's an intentional misrepresentation of Israel's Law of Return (https://en.wikipedia.org/wiki/Law_of_Return), which allows any Jewish person to move to Israel and then become a citizen. It doesn't mean that every Jewish person anywhere in the world is automatically an Israeli citizen whether they want to be or not, but some people like to say that.
>On the day of arrival in Israel, or occasionally at a later date, a person who enters Israel under the Law of Return as an oleh would receive a certificate confirming their oleh status.
On the very day they step off the boat or plane. This isn't the case of "anyone who comes to the US and waits 10+ years might finally get to become a citizen". Seems pretty fucking automatic.
The Wikipedia summary is oversimplified, it's very easy but you do have to affirmatively express an interest and fill out an application (https://www.gov.il/en/service/declaration_of_intent_to_recei...). They don't literally hand it to you when you get off the plane, and even if they did you still can't point to any Jewish person and declare that they must be a citizen of Israel. Most Jewish people have never even been to Israel.
Maybe you're arguing that since it's so easy, all Jewish people in Congress are effectively dual Israeli citizens even if they never actually apply for citizenship. In that case, you'll also be shocked to learn that every single person in Congress is a dual citizen of Dominica, which can be obtained without ever setting foot in the country by just paying $100,000 (https://www.cbiu.gov.dm/dominica-citizenship/). Everyone in Congress can afford that, so we might as well say they've already done it.