Israel's Labor Party once made that mistake. They referred to the Likud's Menachem Begin supporters as "riff raff," and all it did was increase Likud support in the Israeli voting public and cause long term damage to itself. Today, the Likud is still in power and the Labor party, even after a major rebranding and then name change is smaller than ever.
Hillary Clinton: Half of Trump Supporters Belong in 'Basket of Deplorables'
Hillary Clinton urged supporters late Friday not to be complacent about Donald Trump's chances of winning the election, saying half of his backers were "desperate for change" but the other half belonged in a "basket of deplorables."
Appearing at an LGBT gala fundraiser where Barbra Streisand performed, Clinton said many of the GOP candidate's voters were "racist, sexist, homophobic, xenophobic, Islamaphobic, you name it."
Hillary, I hate to break it to you, but when you're running for office you are supposed to try to convince those who support your opponent to change camps and support you, not insult them and turn them away. You're just proving how unsuitable you are to lead a country, any country.