DENVER (CBS4) – Both campaigns say the election is now in the hands of supporters, not the candidates. It’s the supporters working at the grassroots level getting out the vote that could determine the winner.

If there were a Romney volunteer of the year award, Judy Merkel would be in the running. She’s put her life on hold this year to put Mitt Romney and Paul Ryan in the White House.

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“We’re all on. We understand we need to be on the ground going door to door,” Merkel said. “We need to be on Facebook. We need to be in here making these phone calls.”

Merkel says she’s working sun up till sundown these days to turnout the vote. Volunteers like her are the key to the Romney ground game. The campaign says its seen a groundswell of grassroots support over the last couple months with the first debate being a turning point.

“We had to double the number of phones we had in some of our offices just to accommodate all the volunteers,” Colorado Romney Campaign Manager James Garcia said.

And then there was the Red Rocks rally.

“If there would’ve been a lid on the Red Rocks we’d of blown it off,” Merkel said. “I mean it was just awesome.”

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But there’s a high-tech component to their voter outreach as well. Using sophisticated data-mining technology, they track everything from voting histories to what Internet sites people visit to compile lists of likely supporters, drilling down to the micro level swing voters in swing counties.

They can tell who the undecided women are in Jefferson County, for example, and they’ve courted them aggressively.

“They are the ones that we’re having conversations with and letting them know that this election is about our economy,” Merkel said.

“Every single tool at our disposal, we’re utilizing it,” Garcia said.

Team Romney says it’s knocked on three times more doors and made twice as many phone calls this election. It appears to be paying off in early voting because Republicans hold the edge.

“The game plan is here and we’ve got it and we’re just going to ride it through to the end,” Merkel said.

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The Romney campaign says it has contacted 2.5 voters in Colorado so far and 400,000 last week alone.