Donald Trump’s team has hired veteran conservative organizer, David Bossie, to help build the campaign’s voter-turnout operation.

“A friend of mine for many years. Solid. Smart. Loves politics, knows how to win,” Trump told The Washington Post.

According to The Post,

Bossie participated Thursday in strategy sessions at Trump Tower where he was introduced to campaign aides and Trump associates, according to Trump campaign manager Kellyanne Conway. Conway said Bossie would be assisting her with managing day-to-day operations and with strategic planning. “He’s a battle-tested warrior and a brilliant strategist,” Conway said. “He’s a nuts-and-bolts tactician as well, who’s going to help us fully integrate our ground game and data operations, and help with overall strategy as my deputy.” Bossie will also work on crafting attacks against Democratic presidential nominee Hillary Clinton, mining past controversies involving her and former president Bill Clinton, and cultivating Trump’s bond with conservative activists.

Democrats were sharply critical of Bossie, who has been running Citizens United, a conservative advocacy group.

“This is the latest sign that Donald Trump has put the most extreme elements of the right-wing fringe in the driver’s seat of his campaign,” said the chairman of Hillary Clinton’s campaign, John Podesta. “He has devoted his career ever since to trying to tear down Hillary Clinton. For months now, Citizens United has been acting as an arm of the Trump campaign, and this hiring of Bossie now makes it official.”

Bossie has worked with Trump’s team in prior political campaigns. According to The Washington Post,

He is a friend of [campaign CEO Steve] Bannon and Conway whose political projects have often overlapped with his own. He is close to the secretive Mercer family, who have funded his organizations and been major backers of Trump’s candidacy. That leaves three Mercer allies — Bannon, Conway and Bossie — atop the Trump campaign. Hedge-fund investor Robert L. Mercer and his daughter, Rebekah, were key players in urging Trump to reshuffle his campaign this summer. Casino magnate Steve Wynn, an influential Trump ally, is also a friend of Bossie’s. Until this week, Bossie was president of Citizens United, the hard-line advocacy outfit that has mounted digital, film and advertising campaigns against President Obama’s agenda and against moderate Republicans. Bossie will take a leave of absence from Citizens United for the duration of the campaign. And he has left the “Defeat Crooked Hillary” super PAC, which he had been running since June.

Bossie has written numerous articles for Breitbart News. He helped build opposition to House Speaker John Boehner, he opposed amnesties for migrants, he pushed Republicans to develop a replacement for Obamacare, he has campaigned for religious liberty, and he defended Americans’ free speech by winning the Citizens United case at the Supreme Court.

During that Citizens United debate, a top lawyer working for President Barack Obama claimed legislators have the constitutional power to stop publication of books and movies that are critical of politicians. The court fight began when Bossie defended his constitutional right to produce a 2008 movie critical of the Clintons, titled “Hillary, the Movie.”

“Since the Citizens United decision there is more free speech in America — and, importantly, no evidence that corporations have been able to buy an election,” Bossie wrote in 2016. “In fact, the candidates with the biggest super-PAC war chests have often lost. Jeb Bush, who spent more than $100 million before dropping out of the Republican primary on Feb. 20, is just the most recent example.”

Bossie also produced a movie about the Democrat-backed “Occupy” movement, which was active in 2012. The movie is “Occupy Unmasked.”