Shakeups Continue in Donald Trump Campaign, With Field Director Departing

— -- In a sign of more turmoil for the campaign of billionaire Donald Trump, the man charged with hiring volunteers and building ground operations ahead of state primaries across the country, announced he is departing.

“I am voluntarily leaving,” field director Stuart Jolly confirmed to ABC News today. The senior member of the Trump team later added that he “would do it all over again” but it was time for “new leadership to take the reins.”

Jolly’s departure comes on the heels of several changes in the GOP front-runner’s team. It was just last week the campaign announced the hiring of veteran operative Paul Manafort to serve as convention manager, charged with securing the delegates needed for Trump ahead of the Republican party convention this July in Cleveland, Ohio.

"Trump wins in states that we have to win to win the presidency. ... We have appealed to Independents and Republicans,” a confident Manafort told ABC News' George Stephanopoulos on Sunday on "This Week." "We understand how to do it. People are coming on board the Trump campaign now who have experience in this process. We're building our networks out."

Sources within the campaign told ABC News that Manafort held a senior staff meeting Saturday afternoon at Trump Tower, where he laid out his vision for how the candidate can secure as many delegates as possible with an ultimate goal of clinching 1,237 ahead of the convention. As part of that meeting, sources said Manafort discussed hiring more staff and redefining the roles of current staff members.

Tensions have been high within the Trump campaign as some members of the team have pushed back against campaign manager Corey Lewandowski. On one of his first days on the job, a source with direct knowledge confirmed Manafort held a meeting with Trump and Lewandowski -- the veteran campaign leader often clashing with the first-time manager during that interaction.

The Trump campaign declined to comment.

The last month has been rocky for Lewandowski, who just last week saw battery charges dropped against him for an encounter he had with a reporter for the conservative media outlet Breitbart during a Trump press conference in March.

On the day charges were dropped, Trump was hosting a meeting with several Jewish media reporters at his office. According to reporters in that meeting, Lewandowski announced in the room that charges had been dropped.

“I’m proud of you, Corey,” Trump said on a recording of the meeting. “He wasn’t quite as effective for the past couple of months.”