US President Barack Obama makes calls to volunteers who have helped his re-election cause, from the German Village election campaign office in Columbus, Ohio, Nov 5, 2012, on the eve of the US presidential elections. [Photo/Agencies]

CHICAGO - "I'm calling with President Obama's grassroots campaign... We wanted to remind you about the upcoming election on Tuesday, Nov 6."

For up to six hours a day, Jennifer Beasley, a blonde volunteer in her 20s at a Chicago office of US President Barack Obama's reelection campaign, made hundreds of phone calls like this to voters in Illinois and neighboring states via a computer-based automatic dialing system.

On the eve of the final showdown of the 2012 US presidential race, both campaigns of President Obama and his Republican challenger Mitt Romney have reportedly given up winning the hearts of undecided and independent voters, and turned to making the final dash to drive up voter turnout, especially among their own supporters.

Debbie Mesloh, media coordinator for the Obama campaign office on the fifth floor of a building on Chicago's South Wabash Avenue, told Xinhua in a Monday interview that there were about 130 volunteers like Beasley working there, most of them were assigned to call voters for support in recent days.

The office locates only a few miles away from the Obama campaign headquarters at the Prudential Building in downtown Chicago, which has been closed to the media ahead of the Election Day.

Beasley, a human resources consultant at a local company, started her first-day service at the office from 9:00 am Monday. She told Xinhua that she made over 100 calls in just three hours to voters in Iowa, asking them to vote for the incumbent president on the Election Day.

"We ask them if they are aware of the polling place and give them the information of the polling place, and ask them if they need a ride to the polling place. And we ask them if we can count on their votes for President Obama tomorrow," Beasley said.

She admitted that there were mixed responses. "Some are for the president. Some are for the Republican candidate. And there are many more who don't answer or just hang up," she said, adding that she would do one more day on Tuesday to make last efforts to appeal to voters.

Another volunteer Marc Shinderman, a 70-year-old retired physician, said he also made around 100 calls in the morning, but only half of them were answered and no more than 10 percent of those he called said they would actually vote on Tuesday.

Looking a bit frustrated, the grey-haired volunteer said: "It's not about the persuasion. It's a way to remind them of voting if they have not."

Philin Phlash, a freelance photojournalist who got the time to volunteer because there is not much working opportunity for him out there, planned to distribute Obama campaign posters and place signs in as many neighborhoods in Chicago as possible. He said he had the idea when he noticed there were very few election signs in his own neighborhood. Though currently without a job himself, Phlash said he still wanted to work for Obama because he thought the president "is the best man for jobs".

"People volunteer because they care," he stressed. "That's my way to contribute."

Earlier on Monday, both Obama and Romney made their final appeal for their supporters to get to the polls on the Election Day.

Obama reportedly said "if we don't turn out the vote, we could lose a lot of the gains we've already made," While Romney pleaded for "every single vote".

Latest polls conducted by major US media outlets showed that both candidates are still neck-in-neck in the race.