The country’s changing demographics have transformed the political landscape of Western states like Colorado and Nevada, where the surging Latino population could be the key difference. Nevada’s Hispanic population grew by 35 percent over the last decade; in Colorado, it was 16.9 percent. The Latino vote was an important part of President Obama’s winning coalition in 2008, and polls consistently give him a substantial lead over Mitt Romney among Hispanics.

Colorado

Jefferson and Arapahoe counties, both encompassing suburbs of Denver, are generally regarded as “true bellwethers,” according to Kyle Saunders, a professor of political science at Colorado State University. President Bush won both counties in 2004, but Obama reversed that in 2008, running up a winning margin of about 25,000 votes in both counties. Saunders said that Larimer and Weld counties are also likely to be close and bear watching. Larimer flipped from Bush to Obama in 2008, while John McCain held onto Weld.

Substantial blocs of Latino voters could sway the result in Adams, Arapahoe, Jefferson, Larimer and Weld counties, Saunders added. Early voting has allowed 1.7 million Colorado voters to cast their ballots already, and registered Republicans have outnumbered Democrats so far. To regain the edge, Obama will need to either turn out more registered Democrats or win over the unaffiliated voters who make up about a third of Colorado’s electorate -- both outcomes within reach for the president, Saunders said.

Much will hinge on how successful the two campaigns have been in registering and mobilizing voters. The number of registered voters in Colorado grew by about 265,000 between February and November of this year, with an almost equal number of voters registered as Republicans and Democrats. That leaves some 1.3 million unaffiliated voters, whom both campaigns have courted heavily.

Nevada

Here’s a true swing state: In the last six presidential elections, the state has gone to an even three Republicans and three Democrats.

Massive population growth has transformed Nevada from a dependable Red State to a dogfight. But while President Barack Obama won by 12.5 percentage points in 2008, the lingering housing crisis has ravaged the state almost unlike any other. Recent polling shows Obama with anywhere with a one to five percent lead over his Republican challenger Mitt Romney, an advantage that has been -- so far -- confirmed by the state’s early voting turnout.

About 700,000 of the roughly one million voters expected to cast their ballots this year took advantage of the state’s two-week early voting period, according to the United States Election Project. Registered Democrats accounted for 43.9 percent of the votes already cast, compared to the 37 percent from Republicans. While that already gives Democrats a 7 percent lead, political scientists have been quick to note that Obama had a far wider advantage during early voting in 2008, when Democrats outperformed Republicans by almost 12 points.

Although the vote breakdown is still unclear, the Washington Post reports Democrats held a substantial lead -- about 70,000 -- in the state’s populous Clark County, where Las Vegas is located. Democrats have targeted Nevada’s growing Hispanic neighborhoods -- Obama himself has made 10 campaign visits to the state -- while Republicans have concentrated on the outlying suburbs and smaller counties that went for John McCain in 2008.

Romney has made eight trips to Nevada, while his running mate, Paul Ryan, has made another five campaign stops. The Republican ticket’s message of reinvigorating the nation’s broken economy certainly has some pull in the Silver State: It has the nation’s highest unemployment rate at 11.8 percent, and median household income has dropped $9,900 since 2008. Plus, the state still has one of the highest rates of home foreclosures in the country, an area Obama has been accused of falling flat on during his first term.

Nevada’s Washoe County, where Reno is located, is the battleground to watch on Election Day. Obama won the county by 12 points in 2008 -- the first time it had gone to a Democrats since 1964. But polling suggests Republicans and Democrats are neck-and-neck this year, placing more pressure on the GOP ticket to encourage voter turnout from Republicans and independents.