Some 200 protesters, according to local law enforcement officials, gathered Sunday near the residence of billionaire David Koch, who held a private fund-raiser attended by Mitt Romney at his home in Southampton.

The protesters, taking issue with the amount of money Koch and his brother Charles are likely to spend in the race, carried signs and beat drums as they marched along with water near Koch's residence and chanted, "Our elections aren't for sale," and "Whose beach? Our beach."

As they walked to the Koch residence, they passed the homes of fashion designer Calvin Klein and financier Leon Black. One group carried a large sign that read, "Romney has a Koch problem," while a plane flying overhead carried a banner with the same message.

David Koch, and his brother Charles are controversial figures in the Republican Party who support conservative and libertarian causes. Backers of the group Americans for Prosperity, the pair of industrialists are expected to spend tens - if not hundreds - of millions on Republican causes this year.

The protesters said they represented groups including MoveOn.org, Occupy Wall Street, Occupy Long Island, Occupy Huntington and the Long Island Progressive Coalition.

"We're here because of David Koch and his vow to purchase a president. He's vowed to spend no less than $50 million, and I've read the Koch brothers are willing to spend up to $400 million doing that. It doesn't sound like democracy to me," said Anthony Zenkus, with Occupy Wall Street.

Mark Epley, mayor of Southampton, characterized the demonstrations as "going well so far."

The Koch residence was surrounded by a high level of security, including two dozen personnel stationed outside the Koch residence along the beach.