All the way back in 1973…
https://www.jta.org/1973/04/17/archive/fulbright-israel-controls-senate
Sen. J. William Fulbright claimed on the CBS “Face the Nation” television program yesterday that the Senate was “subservient” to Israel and prevented the Administration from applying pressure on that country. The Arkansas Democrat, chairman of the Senate Foreign Relations Committee, said the U.S. possessed the leverage on Israel because “we supply all the wherewithal –or a major part of the wherewithal–to finance or to pay for everything Israel does.” But, he added, this leverage could not be applied because “Israel controls the Senate.”
Fulbright said, “The Senate is subservient to Israel, in my opinion much too much. We should be more concerned about the United States interest rather than doing the bidding of Israel This is a most unusual development.”
He also expressed opposition to the Jackson Amendment linking most favored nation treatment for the Soviet Union to the removal of emigration restrictions by that country. But Fulbright said the Senate would probably approve it. He said he had supported previous Administration plans to achieve a Middle Eastern settlement, but Israel’s objections were supported by the Senate.
“The great majority of the Senate of the United States–somewhere around 80 percent–are completely in support of Israel, anything Israel wants. This has been demonstrated time and again and this has made it difficult for our government.” Fulbright said.