As proven by Philip Graves in 1921, parts of the Protocols were copied directly from The Dialogue in Hell Between Machiavelli and Montesquieu by Maurice Joly, released in 1864. This text is not antisemitic, rather it is a theoretical political discussion about the merits of liberalism versus despotism with each titular character arguing for the one they championed in life.
Three specific lifted quotes were listed on Wikipedia, and I found a text of the Dialogues to verify all three. Two of the quotes are spoken by Machiavelli and one my Montesquieu. The Machiavelli despotism quotes brag of control of the press, which the speaker of the Protocols assigns to the insidious government to be, and the Montesquieu quote is related to the charging and compounding of debt as oppression of the payer.
The nature of the Dialogues was a satirization of the reign of Napoleon III of France, and largely a critique of despotism, inherited political power, and conservatism in general. In fact, the author was imprisoned for its release. The satirized totalitarian state discussed in the work is presented as fact with cherry picked sinister quotes and entire themes, such as control of information and injustice in the repayment of debts, are lifted and repurposed in the Protocols.
These direct quotes suggest that the author of Protocols likely read the Dialogues themself, but its widely considered possible that they may also have taken ideas from an earlier piece of anti-semetic writing by Hermann Goedsche published in 1868 that also contains theorized references to the Dialogues and a shadowy evil Jewish organization, notably simular in concept to the organization described in the Protocols.
Inspired by these two previous works, pieces and summaries of the Protocols were taught to school children in Nazi Germany, and are inspirations for modern conspiracy theory movements such as Qanon and “Big Pharma.” The chain of deceitful and racist propaganda remains unbroken and still holds sway in our modern world.