DENVER - In the key presidential election swing state of Colorado, the deciding votes are expected to be cast in three bellwether counties -- Arapahoe, Jefferson and Larimer.
Unsurprisingly, the campaigns of Republican presidential nominee Mitt Romney and President Barack Obama have been intensely courting these counties -- not only with candidate rallies, but also with telephone banks, campaign mailers and door-to-door lobbying.
In a nation that's a checkerboard of Republican red states and Democratic blue states, Arapahoe, Jefferson and Larimer are known as purple counties -- where voters are pretty evenly divided between Republican, Democratic and unaffiliated groups.
Political experts place greater importance on Arapahoe and Jefferson counties, because they have more votes than Larimer County
"Cleary, those two counties -- perhaps three counties -- hold the keys to Colorado's nine electors. Whoever carries those counties, by definition, will carry Colorado," said Eric Sondermann, an independent political analyst.
"But beyond that they could hold the keys, not to just Colorado, but to the entire Electoral College and the Oval Office," Sondermann stressed.
"Because Colorado could be… the decisive state tomorrow. If Romney is able to somehow get Ohio, plus the Southeastern states and if Obama holds serve in Wisconsin, Iowa and Nevada, then Colorado is the state," he said.
"But, in another way, those counties could hold that key because, as far as I'm concerned, they're bellwether counties not just of what's happening in Colorado, but they're national bellwethers as well. So the (voting) trend there is likely to be the trend you see elsewhere," Sondermann said.
Katy Atkinson, another veteran Colorado political consultant, agreed that the swing counties are key to winning the state.
"If a Republican candidate or a Democratic candidate has the kind of message that appeals to a majority of voters in Jefferson County and a Arapahoe County, odds are very good that message is going to win him -- or her -- the election," Atkinson said.
Democratic Party strategists push to generate an overwhelming majority of votes in their strongholds of Denver and Boulder counties. Republicans likewise strive to maximize their votes in conservative El Paso and Douglas counties.
But both parties know the swing counties are where Colorado elections are won or lost.
And, for individual races, these influential counties can swing both ways.
Atkinson pointed to the "huge differences" in the candidates swing-county voters backed in the 2010 election. They helped elect Republican Secretary of State Scott Gessler and Democratic U.S. Senator Michael Bennet."
"So, they're ticket splitters in those counties," Atkinson said.
Years of polling indicate that winning moderate women voters is key to victory in the swing counties, she added.
"So, if a candidate wants to carry those counties -- and you need to carry those counties to win, whether you're a Republican or a Democrat -- you have to have a message that's going to appeal to female voters," Atkinson said.
The numbers tell the story of how closely these counties mirror election victories in Colorado.
In the 2008 presidential election, Barack Obama beat John McCain by carrying Arapahoe County 55.70-to- 42.80 percent, Jefferson County 53.30-to-44.40 percent and Larimer County 54-to-44.30 percent.
Obama won Colorado by 53.20 percent to 44 percent for McCain.
In the 2004 presidential election, George W. Bush beat John Kerry by carrying Arapahoe County 51.40-to-47.50 percent, Jefferson County 51.80-to-46.60 percent and Larimer County 51.80-to-46.60 percent.
Bush won Colorado by 51.70 percent to 47 percent for Kerry.
Burt Hubbard, a veteran Colorado investigative journalist and editorial director of the I-News news service, compared election results for the swing counties and the state in two presidential races (Obama-McCain and Bush-Kerry) and two U.S. Senate races (Bennet-Buck and Ken Salazar-Pete Coors) going back to 2004.
"If you look at all four of those races and look at the voting percentages for Arapahoe, Jefferson and Larimer counties and then compare them to the statewide numbers, it's eerie, they're almost the same," Hubbard said.
In the final drive for victory, Atkison said it's not the big Romney or Obama rallies that will make the difference.
"What is more important is how much attention they're putting into their get-out-the-vote program in those counties. That is huge," she said. "They are the most important thing going on right now."