Hillary Clinton’s unofficial political adviser Sidney Blumenthal told the Huffington Post in a Facebook Live chat Thursday that “nativism” and “racism” define Donald Trump more than anything else.

In 2008, “they [were] going to eliminate Hillary Clinton and instead they make monkeys of themselves,” Blumenthal said of Republicans’ plans when Clinton first ran for president.  So “the base gets more and more angry,” he continued;

Trump grabs control of that anger and in particular one issue, and that issue is immigration. Nativism and racism are at the core of Trump’s appeal. Without it there is no Trump [in 2016]. He defeats the Republican Party as it was, represented by Jeb Bush, and the conservative movement as it was, represented by Ted Cruz. So both the Republican Party and the conservative movement have been defeated by this character, who now is the dog who’s caught the firetruck.

“Nativism and racism are at the core of Trump’s appeal. Without it there is no Trump,” Blumenthal said, adding:

The base has been enflamed and galvanized by their leadership in order to win various election cycles, and in each cycle they promised they would overthrow Democrats and they would reverse all progressive legislation…

They’re infuriated that Obama won in 2008; they were promised he wouldn’t. They were furious at Bush in violating so-called free market principles.

Blumenthal frequently offered his political advice and spurious Libya-related expertise to Clinton during her tenure as Secretary of State. In one email exchange, he expounded on John Boehner’s rise to the speakership after Republicans won the House in the 2010 midterms, telling Clinton:

“The House Republicans have already planned to primary all Senate Republican moderates in the next cycle. Olympia Snowe is a particular target…In the Senate, Jim DeMint continues to be a Fifth Column of the right, allied to the House Republicans, against remaining Senate GOP moderates. He will be reinforced after this election with Rand Paul, et al. Paul, of course, hates Mitch McConnell, and vice versa…

McConnell’s statement the day before the mid-terms that the goal of the GOP is to make Obama a one term president is, in fact, their agenda. Everything in the House and Senate will be bent to that end…

Boehner is despised by the younger, more conservative members of the House Republican Conference. They are repelled by his personal behavior. Boehner has already tried to buy the members with campaign contributions and committee assignments, which he has already promised to potentially difficult members. His hold is insecure. He is not Gingrich, the natural leader of a “revolution,” riding the crest into power. He is careworn and threadbare, banal and hollow, holding nobody’s enduring loyalty. Boehner is beholden and somewhat scared of his base. He twitches when they make gestures that might undermine his position. His impulse is to hand out money.”

For his 2016 race, Trump has embraced a non-racial, pro-American, nationalist pitch, saying “Make America Great Again.”