Long Island donors contributed $9.9 million to the three fundraising committees aiding Romney and $6.2 million to the committees helping Obama, an analysis of FEC filings found.
That difference narrowed after one Long Island billionaire gave $5 million to the super PAC backing Obama, trumping the $3 million two other wealthy Long Island investors donated to the super political action committee supporting Romney.
The biggest reason for the difference was repeatedly pointed out last year by key Long Island Democrats: Romney visited Long Island to raise money and Obama did not.
"The donations we raise on Long Island come from smaller donors," said Long Island businessman Robert Zimmerman, a Democratic National committeeman and a major fundraiser for Democrats and Obama.
"People like myself who raise money for Democrats on a national level literally get in our car and drive to meetings at local diners and people's homes, asking for contributions and making the case for people's support," he said.
In September, First Long Island Investors chairman and chief executive Robert Rosenthal, of Syosset, held two fundraisers that raised $4 million, Cox said.
"What I found is there is a lot of new wealth in Nassau County," Cox said, that's generated by local entrepreneurs.
Obama won more votes on Long Island, but Romney made a better showing there than the state overall.
Statewide, Obama won 63.3 percent of the vote to Romney's 35.2 percent.
Statewide, committees for Obama raised $82 million to the committees for Romney's $51.7 million, filings show. And Priorities USA Action, the super PAC backing Obama, collected $17 million compared with the pro-Romney Restore Our Future's $15.8 million.
In the first $1 billion presidential election, fundraising on Long Island reflected the national trends reshaping the campaign finance landscape.
Two distinct trends emerged -- the outsized influence of very wealthy donors funding super PACs, which may raise and spend unlimited amounts of money, and the growth of the number of small donors.
"Everybody sees this as a pioneering of a new system of campaign finance," said Sheila Krumholz, executive director of the Center for Responsive Politics, a nonpartisan group that tracks political money.
"There are no limits, no natural stops on this system," she said, and no evidence new laws will be passed to change it.
Consider the difference between small and big donors.
About 6,200 Long Islanders made an average of four $45 donations each that raised $1.1 million for Obama's presidential campaign committee, Obama for America.
Yet just two Long Islanders gave nearly three times the amount donated by those thousands of small donors in just a handful of checks to Restore Our Future. Tiger Management founder Julian Robertson of Locust Valley gave $2 million and Renaissance Technologies co-chief executive Robert Mercer of East Setauket gave $1 million.
Renaissance Technologies founder and chairman James Simons of East Setauket, however, trumped his chief executive and Robertson. Simons gave $5 million to Priorities USA Action in three checks written in each of the three months before the election.
While acknowledging the impact of super PAC donors, Krumholz also pointed to the power of small donors.