Meg Whitman, Hewlett Packard CO (HP) CEO restated her opposition to Donald Trump and further compared him to fascist leaders Adolf Hitler and Benito Mussolini, according to media and two sources. The latter’s comments came Friday at a conference hosted by previous Republican nominee Mitt Romney, while she challenged U.S. Speaker of the House of Representatives Paul Ryan on his endorsement of Trump, as reported by the Washington Post on Saturday.

This wasn’t the first time that Whiteman states her opposition to Trump, in February, the she said he was “unfit” to be president.

Whitman has been keenly working to put an end to Trump’s nomination, and part of her plan was an anti-Trump Super PAC fundraising campaign.

Ryan, addressing the 300 attendees of the session, stated clearly the difficulty he had with the decision to endorse, including pressure from House Republicans to lend his backing to Trump.

However, Ryan endorsed the New York businessman in early June, breaking with a number of establishment Republicans who see Trump’s rhetoric as damaging to the party. The opponents include Romney, Republicans’ 2012 presidential nominee, who chose Ryan as his running mate, and has also criticized Trump in recent weeks for attacks he has made on the Mexican-American judge presiding over a case against him.

As the presumptive nominee, Trump now has to balance maintaining the outsider style that helped propel him to the nomination, while courting Republican insiders, who could be critical to financing a general election campaign against a well-funded Clinton.

Trump on Saturday showed no inclination to make peace with his critics. He went on Twitter to note how Romney “choked like a dog” when he lost to then-incumbent President Barack Obama in 2012 and reiterated it at his campaign stops.