Midterms usually mean only one thing to most Temple University students - tests - but on Saturday about 1,500 of them had the midterm election on their minds, with President Obama to cheer them on.

"Are you fired up?" he asked the effusive crowd, their cellphones aloft to capture the moment inside the Student Pavilion on 15th Street near Norris. Many at the rally were members of Temple's organization of student Democrats, which was canvassing through the weekend to get out the vote.

The Temple appearance - followed by an unscheduled stop at Famous Fourth Street Deli, where Obama sat down among the astonished diners for a quick lunch - was the second time this month the president campaigned in the city for Democratic candidates in the election Tuesday, in a series of events called "Moving America Forward." After he climbed aboard Air Force One at Philadelphia International Airport at 1 p.m., he went on to Bridgeport, Conn., and Chicago for more of the same.

"The fact of the matter is that we are in a difficult election," Obama said at Temple. "And unless each and every one of you turn out, and get your friends to turn out, and get your families to turn out, then we could fall short. And all the progress that we've made over the last couple of years can be rolled back."

Democrats on Tuesday face the possibility of losing their comfortable majority in the House and also losing seats in the Senate, as well as several governorships.

The president told the crowd - which included some protesters with signs from the anti-Obama Americans for Prosperity group - that the key to the election is "not just to show up here. It's not just to listen to speeches. It's to go out there and do the hard work that's going to be required to bring this home."

And he posed a challenge: "What I need this weekend is 20,000 doors knocked on by all the volunteers who are here today."

After his speech, which lasted about eight minutes, Obama's motorcade streamed down Broad Street and turned east on to Bainbridge, coming to a halt at the venerable Famous Deli. There, along the knish-and-coldcut-lined cases at the aisle leading to white-tiled dining rooms, he and U.S Sen. Robert Casey (D., Pa.) greeted the lunchtime crowd, stopping here and there for smalltalk and pictures.

The two eventually were seated for their own lunches. In shirtsleeves, Obama dined on a corned beef reuben and potato pancakes and drank sweet iced team; Casey chose the pastrami.

Sitting at the table across a narrow aisle were a startled Anthony Lawton and his girlfriend, Murph Henderson. "Oh my god, we had no idea!" Lawton said later, of what started out as a garden variety lunch visit. "They just happened to put him next to us."

Lawton, a local actor with a long trail of credits on Philadelphia stages who is currently appearing in the Arden Theatre's The Threepenny Opera, pulled out his cell phone and called his mother. "She told us to tell him she supports him and that she feels bad for the potshots people take," Lawton said.

So they did. And Obama essentially told them not to be concerned. "He said, 'Oh, that's part of my job.' "

Contact staff writer Howard Shapiro at 215-854-5727 or hshapiro@phillynews.com.