Trump's words are an incitement to the type of political violence that touched me personally.

Donald Trump’s utterings about “Second Amendment people” taking matters into their own hands to block a President Hillary Clinton’s Supreme Court picks were a new level of ugliness in an ugly campaign season.

In Israel, incitement such as this led to the murder of my father, Prime Minister Yitzhak Rabin, 20 years ago. Because he dared pursue peaceful relations with our neighbors, my father was contemptuously called a traitor, and posters of him dressed as a Nazi war criminal were waved at right-wing rallies.

After his murder, politicians were quick to condemn the assassin as a lone wolf. They conveniently ignored their role in creating a poisoned environment that led someone to believe that taking a life was a justifiable political act.

More than one commentator in Israel and in the U.S. has pointed to the parallels between Israel in the 1990s and America today.

Trump has called Clinton “the devil," claimed that the election might be “rigged," denigrated entire religions, and questioned the impartiality of the justice system.

Intentional or not, the Republican presidential nominee is removing confidence in the democratic form of governance. If an election is seen as illegitimate, if those who supported a candidate are viewed as somehow lesser Americans, then it becomes acceptable — and even appropriate — to work outside the political system.

The social pact that democracies honor depends on words, not weapons, being used to debate issues. It relies on the populace accepting the outcome of elections, as well as on the ability and willingness of government officials to compromise.

But compromise becomes impossible when one’s political opponents are vilified. How can one enter into an agreement with a counterparty that is illegitimate, or worse?

Some critics have called Trump a threat to American democracy. It is not my place to make this claim, and my purpose here is much more limited. But I have been touched by political violence, and I have witnessed the environment that led at least one person to believe such violence was called for.

While I do not expect Trump to modify his behavior, it is incumbent on responsible members of his party to unmistakably condemn these remarks and clearly state that they are unacceptable.

Trump’s words are not just words. They can sow the seeds for something much more sinister.

Yuval Rabin is an Israeli businessman. Follow him on Twitter @yrabin