WASHINGTON -- Seven Long Island businessmen are among the top donors to presidential super PACs and outside spending groups this year, giving a total of $13 million, mostly to help White House bids by Sen. Ted Cruz (R-Texas) and former Florida Gov. Jeb Bush, recent campaign finance filings show.

In the campaign finance landscape transformed by court rulings, megadonors and outside groups are reshaping the presidential race -- bolstering even marginal candidates, taking over core campaign functions and exercising greater influence over policies and politics.

Each of Long Island's big donors gave $100,000 or more to political action committees or nonprofits that by law are supposed to be independent and cannot coordinate activities with the candidates they back.

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The biggest super PAC donor on Long Island -- and in the entire country -- was Robert Mercer of East Setauket, chief executive of the hedge fund Renaissance Technologies.

Mercer spread $11.75 million among three different groups: $11 million to one for Sen. Ted Cruz (R-Texas), $500,000 to another for former tech executive Carly Fiorina and $250,000 for a super PAC supporting Louisiana Gov. Bobby Jindal.

In second was oil barge executive Morton S. Bouchard III of Melville, who wrote two checks totaling $525,000 to the Bush-supporting Right to Rise USA.

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Michael Brown and John Pickett, executives of Long Island's largest car dealerships chain, Atlantic Auto Group, each gave $125,000 to that Bush nonprofit.

Sheila Krumholz, executive director of the Center for Responsive Politics, which tracks political money, said Long Island reflects the changes in political funding and operation.

Several experts say the lines between official campaigns and outside groups have blurred.

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Anyone can give unlimited amounts to the outside spending groups, but donors to authorized presidential campaign committees are limited to $5,400 for the primary and general election.

Those seven top donors from Nassau and Suffolk together gave 10 times as much to aid candidates as the $1.2 million that 700 Long Islanders donated directly to presidential campaigns, the filings show.

Mercer's single $11 million gift to a Cruz-backing super PAC exceeded the $10.5 million that 6,255 donors across New York State gave to presidential campaign funds this year.

Meena Bose, a Hofstra University presidential scholar, said there is little policing of the big donors and largely unregulated outside groups: "In effect, we have private campaigns for public office now."

All seven of Long Island's top donors declined to comment.

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Overall, 340 Long Island individuals and businesses gave to super PACs and political nonprofits, but only $9,089 went to a super PAC supporting a Democrat, Hillary Rodham Clinton.

Pro-Bush groups raised $1.6 million on the Island. But Mets owner Fred Wilpon of Locust Valley put his money on New Jersey Gov. Chris Christie, giving $100,000 to his super PAC.

Outside Long Island, five New York City hedge fund managers each gave $1 million to super PACs or nonprofits.

Louis Bacon of Moore Capital Management and Julian Robertson of Tiger Management each contributed to the pro-Bush Right to Rise USA.

George Soros and Donald Sussman of Paloma Partners Management each gave to pro-Clinton Priorities USA Action.

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Leonard Blavatnik -- through Access Industries, which owns Warner Music Group -- gave to a super PAC aiding Wisconsin Gov. Scott Walker. Access also donated $500,000 to one for Sen. Lindsey Graham (R-S.C.).

New York businessman John Catsimatidis used his companies to donate to four groups: $75,000 to one for former New York Gov. George Pataki, $50,000 to back Bush, $15,000 to support former Virginia Gov. Jim Gilmore and $10,000 to boost Jindal.

George Tsunis of Matinecock, the Chartwell Hotels CEO and Democratic fundraiser whose 2013 nomination as ambassador to Norway failed, said he will support Clinton. But he said he gave $20,000 to a super PAC that backs Sen. Rand Paul (R-Ky.).

"There are people on both sides of the aisle who have supported human rights and religious freedom, particularly the Eastern Orthodox church in Istanbul," he said. "I choose to support to them."