84 Days to Decide: Voters in 4 States Head to Polls to Decide Hard-Fought Races

Polls have closed in the four states holding primaries Tuesday, with insurgent candidates aiming to continue a yearlong trend of upending establishment candidates.

That dynamic is on full display in Colorado, where Democrat Andrew Romanoff has caught up in the polls to incumbent Sen. Michael Bennet in the Senate primary race. Despite Bennet's White House backing, Romanoff has been credited by political observers with running a stronger ground game and building a stronger connection with local movers and shakers in the Colorado political scene.

The Colorado race is a dead heat, and voters also are choosing candidates in Connecticut, Minnesota and Georgia Tuesday.

Of all the elections, the outcome in Colorado may resonate most for the Obama administration.

Not only did President Obama campaign for Bennet and star in a TV campaign ad, but the White House last year dangled the prospect of a federal job before Romanoff in lieu of running against the incumbent. Bennet was appointed to the Senate in 2009 by Gov. Bill Ritter after the White House tapped former Sen. Ken Salazar for interior secretary. Former President Bill Clinton has put his clout behind Romanoff, making robo-calls on behalf of the candidate in the final hours of the race.

On the GOP side, the candidate with establishment backing is also in trouble. Former Lt. Gov. Jane Norton has earned the support of Arizona Sen. John McCain and the National Republican Senatorial Committee, but trails in the polls against Tea Party favorite Ken Buck.

Norton has been trying to separate herself from the Washington insider label Buck's campaign pinned on her.

The other big race in the state is the Republican gubernatorial primary. Ritter, a Democrat, is retiring and Republicans Scott McInnis and Dan Maes are competing for the GOP nomination.

Both held double-digit leads in hypothetical matchups against Denver Mayor John Hickenlooper, who is running unopposed for the Democratic nomination, until controversies surrounding both candidates started to eat into their poll numbers. McInnis was accused of lifting writings about water issues and then blamed his assistant for the problem. Maes, a former businessman, paid out tens of thousands of dollars for violating campaign finance laws.

Former Republican Rep. Tom Tancredo has announced that he will run for governor as a third-party candidate in the fall.

The races in Connecticut have also attracted plenty of attention. Former wrestling executive Linda McMahon has the lead in the polls over two other candidates for the GOP Senate nomination, but that hasn't kept the contest from getting nasty. One of her opponents, stockbroker Peter Schiff, released an ad that repeatedly featured a video clip of McMahon kicking a man in the groin -- a skit from her days with World Wrestling Entertainment. Polls show Schiff trailing behind both McMahon and former Rep. Rob Simmons. The winner of that race will face off against Democratic state Attorney General Richard Blumenthal, who has been under fire for appearing to misrepresent his military record.

The candidates are competing for the seat being left by retiring Sen. Chris Dodd.

In the state governor race, the millionaire businessman who nearly ousted Sen. Joe Lieberman in 2006 is aiming for a comeback. Ned Lamont is facing off Tuesday against former Stamford Mayor Dan Malloy in the Democratic primary. The latest Quinnipiac University poll released Monday showed Lamont leading by 3 points -- within the margin of error.

Lamont beat Lieberman in the Senate Democratic primary four years ago but lost after Lieberman ran as an independent in the general election. He threw his name in the ring for governor after Gov. M. Jodi Rell decided not to seek re-election.

On the GOP side, former ambassador Tom Foley is leading Lt. Gov. Michael Fedele in the polls.

The race for governor in Minnesota is a scramble after incumbent Gov. Tim Pawlenty announced he would not seek a third term.

Former Sen. Mark Dayton, former state Rep. Matt Entenza and House Speaker Margaret Anderson Kelliher are all competing for the Democratic nomination. Meanwhile, state Rep. Tom Emmer is the favorite on the Republican side.

The 63-year-old Dayton's lengthy past in Minnesota politics -- he first ran statewide in 1982 -- gave him broad recognition among the party faithful. A millionaire himself, his campaign's cornerstone was a pledge to make the top 10 percent of Minnesota income earners pay more in taxes to help plug a budget deficit.

Entenza, 48, put more than $5 million into his bid, most from a family fortune.

Kelliher hoped the Democratic-Farmer-Labor Party endorsement she won at the April state convention would give her a ground-game edge against her monied opponents. The 42-year-old promoted a jobs plan tied to additional public borrowing. A primary victory would make Kelliher the first woman to win a major party's nomination for Minnesota governor.

The Independence Party, made famous by former Gov. Jesse Ventura, had a five-candidate primary. Only two, former public relations executive Tom Horner and publisher Rob Hahn, mounted serious campaigns.

And in Georgia, several congressional runoffs are being held.

Newly elected Rep. Tom Graves is trying to keep his seat in a race against GOP challenger Lee Hawkins. Tuesday's runoff is the fourth time since May that voters in the 9th Congressional District in north Georgia have cast ballots.

Rob Woodall and Jody Hice are vying for the GOP nomination for an open seat in the 7th Congressional District. Voters in eastern Georgia's 12th District will also decide whether Republican Ray McKinney or Carl Smith is nominated to challenge Democratic Rep. John Barrow in the fall.

Meanwhile, Republicans Mike Crane and Deborah Honeycutt are running against each other for the GOP nomination in the 13th Congressional District.

Fox News' Alicia Acuna and The Associated Press contributed to this report.