Washington ? Sen. Barack Obama raised $31 million for his presidential primary campaign over the past three months, surging past Sen. Hillary Rodham Clinton’s fundraising machine by nearly $10 million for the quarter to take the lead in contributions in the crowded Democratic field.

Obama became the first Democrat to surpass $30 million in a quarter during a non-election year, a feat his campaign said was accomplished not just with help from wealthy, traditional donors but also with a strong showing among small contributors.

The Illinois senator trails Clinton in most polls, but the favorable performance reported Sunday is expected to increase the pressure on Clinton’s team. Obama was able to outrun Clinton, of New York, even after she began turning for fundraising help to her husband, Bill Clinton, the most prolific money-raiser in Democratic history. The former president will join his wife today in Iowa for their first high-profile joint campaign appearance.

In addition to Obama’s haul for the primary, he collected $1.5 million for the general election, for a total of $32.5 million raised over the past three months.

Clinton’s campaign announced late last week that it would raise $27 million to $28 million for the second quarter, but aides said Sunday that only slightly more than $21 million was in primary donations.

Clinton took in the most money during the first three months of the campaign and is expected to have about the same amount of money in the bank as Obama when they formally file their second-quarter fundraising reports in mid-July. That’s because she transferred about $10 million to her presidential bid in leftover money from her Senate campaign.

Among other Democrats, former North Carolina Sen. John Edwards finished third in the fundraising race this quarter, meeting his $9 million goal after a last-minute appeal from his wife, Elizabeth Edwards, that played off of controversial remarks by conservative television commentator Ann Coulter. Gov. Bill Richardson of New Mexico was not far behind, raising $7 million for the quarter.

Sen. Christopher Dodd, D-Conn., raised $3.25 million for the second quarter, giving him $12.25 million this year.

On the Republican side, former Massachusetts governor Mitt Romney told his fundraising team Friday that its second quarter fell short of the $21 million he raised in the first quarter, leaving an opening for former New York Mayor Rudy Giuliani to take the second-quarter fundraising lead. Giuliani is expected to announce his numbers today or Tuesday.

Sen. John McCain, R-Ariz., was hoping to finish third, with a total of between $10 million and $15 million.