LAS VEGAS – President Barack Obama appeared in a surprise videotaped message at the Netroots Nation conference to thank the slew of progressive media and activists for helping advance a new agenda and urged them to "keep up the fight" ahead of the November elections.

"Thanks," he told the crowd on Saturday, "for helping to change America for the better.

"We're moving America forward," Obama said, invoking the stimulus package, hate-crimes legislation, health care reform, financial reform and various other initiatives. "When we've come this far, we can't afford to slide backwards."

The president received applause at various points during the speech, particularly while mentioning his legislative accomplishments and the turn to more progressive policies since the Bush administration.

While admitting that he understands why some believe "change hasn't come fast enough," he urged liberals to "keep making your voices heard; to keep holding me accountable; to keep up the fight."

Admitting that much work is left to be done in achieving a more progressive America, Obama characterized November as a choice "between going back to the failed policies that got us into this mess, and moving forward with policies that are leading us out."

"Change is hard," he said. "But if we've learned anything these past 18 months, it's that change is possible. It's possible when folks like you remember the fundamental truth of our democracy -- it's that change doesn't come from the top down, it comes from the bottom up. It comes from the netroots, from the grassroots.

"We've done it before, we can do it again," Obama added. "Let's finish what we've started."

Enthusiastic at times, the gathering of thousands of liberals at the conference has also expressed agitation and restlessness towards what they describe as the sluggish pace of progressive change since the 2008 election.

Obama was introduced by House Speaker Nancy Pelosi (D-CA), who appeared in person for a lengthy question and answer session about a wide range of issues.

The following video, Obama's address, was uploaded to YouTube by NetrootsNationVideo.

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