(Image credit: Pablo Martinez Monsivais/AP)

President Obama and Democrats raised a combined $43.6 million in April with sustained financial support from veteran donors while enlisting thousands of new ones, the Obama campaign announced on Twitter.

The monthly haul does not eclipse the president's best fundraising month of the 2012 campaign - $53 million raised in March. But it does keep Obama on pace to top the record-setting total of four years ago.

The Obama campaign, Democratic National Committee and two joint fundraising accounts have together now raised nearly $400 million for the president's re-election effort.  During the 2008 race, Obama topped $746 million.

Behind the impressive sum of cash is an army of nearly 2 million individual contributors backing a second Obama term, officials said. More than 437,000 people donated in April, including 169,500 for the first time. The average donation was $50.

"That makes our campaign different, and it's how we're going to build a winning organization across the country," said Obama campaign manager Jim Messina in a video message to supporters on YouTube.

Messina and Democrats regularly tout the growth and breadth of their grassroots field operation - including teams of volunteers and campaign offices - as giving them a competitive edge over GOP rival Mitt Romney.

Obama opened 42 new field offices and made 120 new staff hires in April, according to Messina.  Most of those are in key battleground states, including Colorado, New Mexico, Nevada, Iowa, Florida, North Carolina, Virginia and Ohio.

"One of the most important things we can do is get our arms around the fact this election is going to be close given the historic challenges the nation faced when the president first came into office," Messina said.

Republicans cast the latest fundraising report as a sign Obama is struggling to generate enthusiasm among his supporters, noting he raised less in April than March and has attended a record-setting 135 fundraisers over the past year.

"Barack Obama is still the fundraiser-in-chief but even he is struggling to sell the American people on his brand of hype and blame that has left millions without jobs, a struggling housing situation and record deficits and debt for future generations," said Republican National Committee spokeswoman Kirsten Kukowski.