Obama campaign: "Welcome to the general election"

Updated 8:55 p.m. ET

(CBS News) The Obama campaign announced the official open of the president's re-election effort.

In a conference call with reporters, Mr. Obama's campaign manager Jim Messina began by saying, "Welcome to the general election."

Messina announced that the president and First Lady Michelle Obama will hold two rallies on Saturday, May 5. The first will take place in Columbus at Ohio State University and the second in Richmond, Virginia at Virginia Commonwealth University.

The announcement to reporters coincided with a text message alert to supporters with the greeting "Big news."

The Obama campaign launches into general election mode after the Republicans "settled for their candidate," Messina said.

Presumptive Republican nominee Mitt Romney swept five primary states Tuesday, Republican National Committee (RNC) endorsed him and one of his challengers, Newt Gingrich, announced that he is leaving the race.

Messina said voters will have the "choice between two distinct records, and two different visions for the future of this country."

"Mitt Romney wants to go back to the future," Messina said.

"Americans shouldn't be surprised that President Obama's campaign will attack Mitt Romney for his experience in creating jobs," Romney campaign spokesperson Andrea Saul responded. "Unfortunately, voters will have to expect that the Obama campaign will be running a campaign based on personal attacks to divert, distract and distort. Like Mitt Romney said last night, 'It's still the economy, and we're not stupid.'"

Although the Obama campaign officially launches its re-election efforts, the president has held more than 100 fundraisers, according to CBS News estimates.

The Republican National Committee filed a complaint with the Government Accountability Office alleging the president is using taxpayers' dollars for events at college campuses to talk about student loan rates this week that they charge are campaign events.

Senior adviser David Axelrod said "it's part of the job of the presidency" to talk to the public.

"We're not going to get hot and bothered by RNC stunts," he said.