Who is Donald Trump's campaign manager Corey Lewandowski?

http://www.bbc.co.uk/news/election-us-2016-35921337

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Corey Lewandowski - the brains behind Donald Trump's unlikely yet wildly successful presidential campaign - may be as brash and unapologetic as his boss.

While Trump's pugnacious style may have made him a front-runner, Lewandowski's rough edges have led to legal trouble for the campaign manager.

The 42-year-old Massachusetts native and former lobbyist was charged with simple assault, accused of grabbing a reporter's arm at a campaign event.

He has denied reporter Michelle Field's allegations and said he will plead not guilty.

He had his start in politics in the mid 1990s after attending the University of Massachusetts and American University, working for several Republican congressmen.

While working for Ohio Congressman Bob Ney in 1999, he was arrested after he brought a pistol into a congressional office building. He later said he brought the gun by mistake.

Mr Lewandowski worked for the Republican National Committee, according to his LinkedIn page, and was a lobbyist for almost eight years.

Most recently before working for Mr Trump, he was employed by Americans for Prosperity, a conservative advocacy group founded by billionaire conservative activist David Koch.

"Corey has tremendous energy, a wonderful vision for politics and the greatest candidate ever, without which none of it works," Mr Trump told the Wall Street Journal before the Republican primary in South Carolina.

The newspaper characterises Mr Lewandowski, who is married with four children, as "brash and ambitious" and that he "demands loyalty" and "subsists on little sleep".

His brush with Ms Fields - who at the time worked for Breitbart News - is not the only time he has been linked to a physical altercation on the campaign trail.

On 19 March, video appeared to show Mr Lewandowski grabbing a protester by his shirt collar during an Arizona rally.

In both his previous job with Americans for Prosperity and his time on the Trump campaign, there have been complaints about him being abrasive with reporters and sexually inappropriate in tone to female reporters especially, and quick to demonise colleagues who challenged him, according to a lengthy report in Politico.

According to that report, Trump campaign members had planned to deliver a letter to the presidential candidate's head of security, expressing concern about Mr Lewandowski's behaviour.

After Mr Trump won both the South Carolina and Nevada primaries, the plan was scrapped.

Others have complained about his alleged hot temper and use of profanity.

Mr Trump has defended his campaign manager, calling him a "great guy" shortly after the incident and tweeting that video footage of the alleged assault shows "nothing".

Mr Lewandowski tweeted shortly after the alleged assault that he had never met Ms Fields, who ended up resigning from her job over the scuffle, much less touched her.

"Mr Lewandowksi is absolutely innocent of this charge," a Trump statement said following the news of his arrest. "He is completely confident that he will be exonerated."

Speaking with reporters on Tuesday, Mr Trump defended Mr Lewandowski again.

"They've really hurt a very good person... I don't discard people... I told him he should never settle this case," he said.