HILLARY CLINTON: Early voting numbers show Clinton's strength in Arizona, other battlegrounds.

Hillary Clinton's campaign has reason for optimism in several swing states -- and appears to have turned Arizona into a battleground -- as millions of Americans vote early. More than 7.3 million Americans have already voted. Democrats have improved their positions in North Carolina, Nevada and Arizona compared to this point in 2012, according to a CNN analysis of the latest early voting statistics. Republicans, meanwhile, have good news in Iowa. Republicans have improved their position there over 2012 -- backing up the polls which suggest it could be the easiest state won by President Barack Obama for Trump to flip this year. And in Florida, where the latest comparable data comes from 2008, Democrats -- buoyed by an increasingly diverse electorate -- have cut deeply into the traditional Republican advantage in early ballots cast so far. These findings represent absentee ballots submitted and early votes cast through Tuesday across 35 states where data are available. Catalist, a data company that works with progressive candidates and advocacy groups, academics and think tanks, connects the data to voter records, allowing a deeper look at who has already cast a vote in this year's election. Across 12 battleground states where data are available, more than 4.6 million votes have been cast. Here's a look at the early voting data from several of those battleground states: Arizona Registered Democrats continue to outpace registered Republicans in early voting. They're ahead by 4,116 votes, a major improvement from their position at this time four years ago, when they trailed by 21,179. Two-thirds of Arizona voters cast their ballots before Election Day in 2012 -- making these early voting numbers crucial to watch for Clinton and Trump. Colorado This is the first presidential election where all registered Coloradans can vote-by-mail. Ballots went out last week, and Democrats have been increasing their advantage over Republicans as people cast their votes. Democrats have outvoted Republicans by more than 10,000 votes, doubling their lead since Saturday. This could be very good news for Clinton, because at this point in 2012, Republicans had the advantage by about 7,600 votes. Georgia More than 583,000 people have already voted in Georgia -- that's a 40% turnout increase from this point in 2012. Voters don't register by party in Georgia, so party breakdown for early voters isn't available. Half the state voted early in 2012. Florida As in-person early voting kicks off in Florida, Republicans are ahead, but by a narrow margin. They currently hold an 18,120-vote advantage, a paltry amount compared to their 113,222-vote edge at this time in 2008. The Clinton campaign has touted its efforts to register Hispanic voters in Florida, and that might be paying off. They comprise about 12% of the early voting electorate so far -- up from 8% in 2008. In addition, the share of the white vote has dropped from 82% in 2008 to just over 77% this year. There were reports of long lines stretching past 90 minutes in Miami-Dade County as in-person early voting began Monday -- with voters telling reporters they were motivated by their distaste for Trump or Clinton. Iowa Iowa, where 43% of the vote came early in 2012, continues to provide a flicker of good news for Trump. Democrats are ahead of Republicans in the latest early vote count, but their margin is lower than it was at this point in 2012, to the tune of about 7,200 votes. This gap isn't as wide as it was last week, but Democrats will need to ramp up their efforts in Iowa if they want to hold the Hawkeye State. Iowa Iowa, where 43% of the vote came early in 2012, continues to provide a flicker of good news for Trump. Democrats are ahead of Republicans in the latest early vote count, but their margin is lower than it was at this point in 2012, to the tune of about 7,200 votes. This gap isn't as wide as it was last week, but Democrats will need to ramp up their efforts in Iowa if they want to hold the Hawkeye State. Nevada In-person early voting kicked off across Nevada over the weekend and Democrats have flocked to the polls. They hold a nearly 15,000-vote lead, a slight improvement from their position in 2012. Overall, early turnout is 18% lower than 2012 but slightly higher than 2008. Nevada is a crucial early voting state. In 2012, 69% of the state's electorate cast their ballots before Election Day. North Carolina Registered Democrats have jumped ahead of registered Republicans by more than 100,000 votes in the Tar Heel State so far, as thousands of voters cast ballots over the weekend. The Democratic edge is slightly higher than it was in 2012. However, if Clinton wants to flip North Carolina blue this year, she'll need strong turnout from African-Americans. At this point in 2012, black voters were 30% of the electorate. They're only about 25% today. North Carolina reduced its early voting window, and the total ballots cast so far is down by more than 180,000 votes compared with 2012, but it's still a critical early voting state. Sixty-one percent of the state voted early in 2012. Utah At this point in 2012, Republicans led Democrats in early voting by more than 31,000 voters. But so far this year, the GOP advantage is only 15,834. That's a drop of about 50% for the GOP in the most surprising state in play in the 2016 election. Still, it's hard to read much into Utah's statistics. The state is a Republican stronghold. But Trump's unpopularity with its Mormon voters -- combined with independent conservative candidate Evan McMullin's focus there -- has turned it into a three-way race, with Clinton hoping to slide past a divided GOP. There's no way to tell at this stage whether those Republican ballots went for Trump, McMullin or someone else. There's also the reality that the popularity of Romney, a Mormon, in Utah in 2012 fueled interest in that cycle. Republicans' advantage today is stronger than the 2,231-voter edge the GOP had in Utah in 2008.