Donald Trump's campaign manager Corey Lewandowski will no longer working with the presumptive Republican nominee's campaign. "The Donald J. Trump Campaign for President which has set a historic record in the Republican primary having received almost 14 million votes, has announced today that Corey Lewandowski will no longer be working with the campaign," Hope Hicks, Trump's campaign spokeswoman, said in a statement.

As the Republican National Convention in Cleveland approaches, Trump is looking to bring more fundraising to his campaign, as well as airing more campaign ads as he heads into the general election. According to The New York Times, Lewandowski had never worked on a national campaign before and many allies and donors had expressed concern over how equipped he was to be Trump's campaign manager. With Lewandowski's departure, Trump's campaign is looking to reignite the campaign and bring in someone with more experience and knowledge on general election campaigns.

Trump is turning his attention to his general election strategy, as he now focuses on defeating Hilary Clinton in November's general election. Lewandowski was previously charged with misdemeanor battery after he was accused of grabbing a reporter after she approached Trump with a question on March 8 in Florida. The charges against him were later dropped.

On Saturday, Trump's campaign sent out an email asking supporters to help them raise at least $100,000 by the end of the day. Hilary Clinton launched a multimillion-dollar campaign ad spree across eight swing states, as she gears towards the general election. According to a Monmouth University poll released on Monday, 47 percent of registered voters back Clinton, while 40 percent support Trump. According to Real Clear Politics, Clinton is currently in the lead against Trump in eight national polls.

With Trump's poll numbers faltering and criticisms from Republican officials mounting, Lewandowski's departure marks a significant change in the campaign's strategy that could have major implications on how the Trump campaign moves forward into the general election.