During an exclusive Republican gathering here [Park City, UT] on Friday, billionaire mega-donor Meg Whitman challenged Paul Ryan over his endorsement of Donald Trump – and, in doing so, compared the presumptive GOP presidential nominee to Adolf Hitler and Benito Mussolini.-- Former gubernatorial candidate (R-CA) Meg Whitman, June 10, 2016, as related by Alex Isenstadt of Politico.
Whitman and Ryan are present for Experts and Enthusiasts, an annual summit convened here by Mitt Romney that brings together his top donors and major political figures. Part of the day’s program included a discussion session between Ryan and former broadcast journalist Campbell Brown.
At one point, according to two sources, during a question and answer session, Whitman, the billionaire chief executive officer of Hewlett Packard, challenged Ryan over his decision to support Trump. In framing the question, according to the sources, she compared Trump to past historical demagogues including Hitler and Mussolini.
Comment: This is both "demagogue" and "comparing" rhetoric, though without direct quotes and context, it's hard to evaluate whether the rhetoric is appropriate.