Donald Trump has hired David Bossie, the president of Citizens United, as his new campaign deputy manager, a move that signals the Republican candidate is likely preparing to go hard after Democratic nominee Hillary Clinton.

Trump announced the hire during a phone call with the Washington Post.

"A friend of mine for many years," Trump said Thursday. "Solid. Smart. Loves politics, knows how to win."

Bossie stepped down as president of the conservative activist group earlier this week, his team confirmed Thursday afternoon.

"Dave's leave is effective at close of business yesterday," Michael Boos, the organization's executive vice president, told the Washington Examiner .

The longtime GOP operative is expected to resume his role as president of Citizens United, a position that he has held since 2001, after the November presidential election.

The new addition to Trump's team has already started work, and reportedly participated in strategy sessions with the GOP nominee's team Thursday.

Trump campaign manager, GOP pollster Kellyanne Conway, told the Post that Bossie would help her manage the campaign's day-to-day duties.

"He's a battle-tested warrior and a brilliant strategist," she 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."

This isn't the first time that Bossie and Conway have crossed paths in 2016 election.

Bossie stepped down recently as head of the Defeat Crooked Hillary PAC, which was launched in June by noted GOP donor Robert Mercer.

However, Defeat Crooked Hillary was founded in June. The organization is really just a retooling of a previous PAC, the pro-Sen. Ted Cruz group Keep the Promise, which Conway headed until she left last month.

Conway personally recruited her successor.

"Very few people have studied Hillary Clinton longer or stronger than Dave Bossie, and I support him in this role as I decide where I can be most helpful in defeating Hillary Clinton," she said in the days before her official exit from the group.

As a new member of the Trump team, Bossie is expected to help fine-tune the campaign's attacks on Clinton.

And as far as going after a Clinton is concerned, Bossie can boast of decades of experience in this area.

"Bossie first began looking into the Clintons as a member of the Senate's special committee on the Whitewater real-estate affair. His work there was noticed by then House speaker Newt Gingrich, who approved tapping him to be the chief investigator for the House's Government Reform and Oversight Committee," the Post reported.