PHILADELPHIA (AP) - Volunteers flocked to Barack Obama last time. This time, the president's campaign is in recruiting mode.
Without a primary challenger in the 2012 race, Obama is trying to rebuild a massive organization of supporters to help boost his efforts in the face of a struggling economy and weakened political standing.
Obama's campaign is holding more than 2,000 events around the nation through the end of the weekend. They include neighborhood gatherings, one-on-one meetings in coffeehouses, phone banks, voter registration drives, door-to-door voter canvassing and house parties.
The goal is to organize the legions of activists who formed the core of Obama's coalition in 2008 - black and Latino voters, women and college students and voters entering the workforce - long before the election a year from new.
Such activities could help determine whether Obama can mobilize enough support to overcome broad concerns among the public over joblessness and the direction of the country, as well as the disillusionment felt by some of his 2008 supporters.
Back then, Obama built a large base of volunteers in dozens of states that held primaries and caucuses and then quickly moved on to the general election.
Many volunteers were drawn to Obama because he was new to the national stage and sounded a message of hope and change.
Now that he's president, Obama has a record that doesn't sit well with some who worked to help him get elected.
His campaign is undeterred.
"Block by block, person by person, student by student, we are going to build the biggest grass-roots effort in American political history," campaign manager Jim Messina said at an event Wednesday at the University of Pennsylvania to kick off a mobilizing effort on college campuses.
Messina told about 250 college and high school students and others watching online that there were 8 million registered voters between the ages of 18 and 21 who weren't old enough to vote in 2008 but would be harnessed to support the president.
Yet, the young voters, many of whom were galvanized in 2008 by the promise of ending the Iraq war, are not an easy sell this time.
Obama won voters between the ages of 18-29 by a margin of about 2-to-1, but polling has shown some signs of softening support as many recent college graduates face high levels of unemployment.
The students heard from Messina, White House policy adviser Melody Barnes and others who trumpeted the administration's support for college aid and efforts to maintain health care coverage for young people.
Kyle Musto, a 17-year-old high school senior from West Philadelphia, said he was undecided as he considers his first vote in a presidential election. "I have friends who are very opposed to Obama. I have friends who are very pro-Obama. I'm very open to anything," he said.
Meetings like the one in Philadelphia are more common because Obama has avoided a Democratic challenger and his team can't point to contested primaries and caucuses as reasons for people to get involved now. So they are finding motivation elsewhere.
As Obama has tried to win passage of his jobs agenda in Congress, party loyalists regularly receive emailed updates from campaign officials urging them to pressure Republican lawmakers by phone, email or Twitter. At the Philadelphia event, students were encouraged to text their ZIP code and the phrase "Greater Together," the name of the young voter program, to the campaign so they could receive more information. Students were also asked to urge their Facebook friends to support the campaign.
The campaign is planning to use January's Iowa caucuses and New Hampshire primary as an organizing tool, too.
The approach resembles the extra attention President Bill Clinton paid on the two states in 1996 even though he didn't have a primary opponent. In the weeks before the early contests, Clinton and administration officials traveled to Iowa and New Hampshire to offer rebuttals of the Republican field while the campaign held events around the state.
Obama's campaign has opened eight offices across Iowa and told reporters this week it had held more than 700 training sessions and made more than 100,000 phone calls to Iowans since the campaign opened in April. In New Hampshire, the campaign is opening its second office this weekend and has logged more than 90,000 phone calls and 2,200 one-on-one meetings across the state, all aimed at boosting turnout and support in 2012.
"You've got to sell this as a building block for the general" election, said Charlie Baker, a veteran field organizer of Democratic presidential campaigns who ran President Bill Clinton's New Hampshire effort in 1996.