President Obama is outpacing his record set four years ago for pulling in small donations, an analysis released Wednesday confirms.

Nearly half of the donors to Obama’s reelection campaign in 2011 gave $200 or less, more than double the proportion seen in 2007, according to the analysis from the Campaign Finance Institute, which tracks money in politics.

Just 9 percent of donors to GOP front-runner Mitt Romney, by contrast, came from the lowest end of the contribution scale, the study shows. Obama raised more money in aggregate from small donors — $56.7 million — than Romney raised overall.

The numbers cement Obama’s reputation as unusually reliant on small-scale donors to fill his campaign war chest. An earlier analysis by The Washington Post produced similar findings, suggesting a persistent trend in Obama’s 2012 fundraising strategy.

The new findings come in the same week that Obama decided to embrace the efforts of a pro-Democratic super PAC, which can raise and spend unlimited amounts of money to aid in his reelection effort. Advisers say the campaign has concluded that the eventual GOP nominee and allied conservative groups are likely to outspend Obama, despite his fundraising record.

The 2011 data show that Obama has relied more on small donations this cycle than he did in 2007, when he raised a larger proportion of his money from wealthy donors before grass-roots supporters drove his fundraising.

Obama had raised only 22 percent of his $96.7 million in 2007 from donors whose contributions aggregated to $200 or less, the CFI study found. That number shot to 48 percent in 2011.

“The president has been able to capitalize on the 13-million person mailing list he assembled in 2008 to launch into small-donor fundraising at a much faster pace than four years ago,” the institute said in a news release.

The CFI study defined small donors as those whose total contributions in 2011 added up to $200 or less. The approach provides a more accurate reading of the number of donors who truly give only a small amount of money to a campaign, as opposed to those who give multiple gifts smaller than $200.

It’s harder to accurately gauge Obama’s reliance on higher-end donors because this year he can raise money jointly with the Democratic National Committee, which can accept donations of up to $30,800 per donor.

Obama’s campaign committee raised $33.4 million from donors giving $1,000 or more last year, compared to $57.9 million from such donors in 2007. However, the president also helped raise $89 million in a joint effort with the DNC, meaning the actual proportion of larger donors is much higher.

On the Republican side, candidates other than Romney also posted relatively strong small-donor percentages last year, though none raised a particularly large amount of money overall. Of those remaining in the field, Newt Gingrich raised 49 percent of his money in 2011 from donors giving less than $200, Rep. Ron Paul (R-Tex.) had 48 percent and Rick Santorum had 32 percent, the data show.

Romney, by contrast, raised two-thirds of his $56.3 million from donors who gave $2,500, the maximum allowed by an individual to a candidate under Federal Election Commission rules.