Would an original meaning analysis, defined as "What would a reasonable person living at the time of ratification have understood these words to mean?", of the free speech clause of the US constitution conclude that knowingly, willfully, deliberately AND demonstrably lying about an elected Official (i.e., claiming "I have talked with over a dozen people and they've all said Senator Shmalahozen raped them when they were children," when one actually has not talked to ANYONE about the topic) is protected speech?
This was actually considered in the United States, when in 2012 the Supreme Court ruled the Stolen Valor Act of 2005 to be an unconstitutional infringement of free speech. In a nutshell, Congress made it a crime to claim military honors that were not earned, as a crime above and beyond normal fraud. When a water district board member got caught for claiming military honors he didn't have, he was convicted but appealed saying his free speech - his "right to lie" was being unfairly silenced.
Ultimately, the Court agreed that there is a constitutional protection for the "right to lie" as a class of free speech, overturning the conviction.
Regardless of original intent, the Supreme Court has at least interpreted what it means today.
(Soon after a nearly unanimous Congress passed the revised Stolen Valor Act of 2013 to criminalize the fraudulent claiming of military decoration in order to obtain money, property, or other tangible benefit.)
They would conclude that the First Amendment to the Constitution was completely unrelated to slander (spoken) or libel (written) defamation of character.
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
Unfortunately, many people today do not understand that the 1st Amendment prohibits the government from curtailing your speech, it does not absolve you from possible civil damages or prevent private individuals from censoring you.
Laws regulating slander and libel in the United States began to develop even before the American Revolution. In one of the most famous cases, New York publisher John Peter Zenger was imprisoned for 8 months in 1734 for printing attacks on the governor of the colony. Zenger won his case and was acquitted by jury in 1735 under the counsel of Andrew Hamilton. The case established some precedent that the truth should be an absolute defense against libel charges. [...] Zenger's case also established that libel cases, though they were civil rather than criminal cases, could be heard by a jury, which would have the authority to rule on the allegations and to set the amount of monetary damages awarded.
The First Amendment of the U.S. Constitution was designed specifically to protect freedom of the press. However, for most of the history of the United States, the Supreme Court neglected to use it to rule on libel cases. This left libel laws, based upon the traditional common law of defamation inherited from the English legal system, mixed across the states.
It wouldn't be until 1964, when the Supreme Court in New York Times Co. v. Sullivan established a standard for proving defamation.
(1964) was a United States Supreme Court case that established the actual malice standard, which has to be met before press reports about public officials or public figures can be considered to be defamation and libel; [...] and hence allowed free reporting of the civil rights campaigns in the southern United States. It is one of the key decisions supporting the freedom of the press. The actual malice standard requires that the plaintiff in a defamation or libel case prove that the publisher of the statement in question knew that the statement was false or acted in reckless disregard of its truth or falsity. Because of the extremely high burden of proof on the plaintiff, and the difficulty in proving essentially what is inside a person's head, such cases—when they involve public figures—rarely prevail.