In the clip, Kaine recounts his time as governor of Virginia, promises to work across party lines, and never mentions his time at the partisan DNC.
"I'm running for the United States Senate because America has big challenges, and I'm convinced that Virginia has answers to help strengthen our nation," Kaine says in the video.
Kaine would enter the race to succeed Democratic Sen. Jim Webb, who announced in February he will retire from office after just one term.
The former governor mulled a Senate run in recent weeks, and had given strong signs he would mount a Senate campaign.
On the Republican side, Kaine could face former opponent George Allen, who lost the Senate seat to Webb in 2006. Allen, who was governor of Virginia from 1994 to 1998, announced his candidacy in January.
Tea Party activist Jamie Radtke has also said he will seek the Republican nomination.
From time to time during this election season we'll be introducing you to ordinary people that our reporters meet out on the campaign trail. Today: a snapshot from a Donald Trump rally in New Hampshire.
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