Tonight is one of the biggest nights remaining on the primary calendar, with primaries in Colorado, Connecticut, and Minnesota. There also is a primary runoff in Georgia. All four states feature important contests at the top spots on their ballots.

Colorado

Senate – In the Colorado Senate race, we have competitive primaries in both parties. In both of these races, it appears that the insurgent candidate could defeat the candidate backed by the Washington establishment. On the Democratic side, it is Andrew Romanoff against appointed Senator Michael Bennet. Bennet has significantly out-raised and out-spent Romanoff. Bennet also has the support of the President and Washington establishment organizations such as the Democratic Senatorial Campaign Committee. Despite these disadvantages, Romanoff has managed recently to  take a small lead according to some polls. (Another recent poll has him trailing slightly.) If Romanoff pulls off this challenge, it will be an impressive feat. This race should be extremely close and likely will be the source of much political navel-gazing tomorrow.

On the Republican side, it is a fight between Ken Buck and former Lieutenant Governor Jane Norton. Norton had the early lead in the race and much of the institutional backing, but has slipped steadily in the polls, allowing Buck to take a decent lead. Buck is the right-wing Tea Party-backed challenger to Norton, similar to Sharron Angle in Nevada and Rand Paul in Kentucky. He has been able to draw on a wealth of grassroots support. Interestingly, this primary fight pits Norton’s Chamber of Commerce endorsement against Buck’s Freedomworks endorsement. A recent SurveyUSA poll had Buck leading by nine percentage points, while a recent PPP has Norton leading by two.

Governor – The Republican primary for governor has turned into a nightmare for Republicans. Scott McInnis was doing well and seemed to be a good candidate until he was caught plagiarizing work that he had been paid several hundred thousand dollars to do. The race now has turned into a real fight between Scott McInnis and ultra conservative (and probably crazy) Dan Maes. Maes believes a decade-old Denver pro-bike plan might be part of a secret UN takeover plot. Add in Tom Tancredo’s decision to run on the American Constitution Party ticket, which could split the conservative vote, and it looks like Democrat John Hickenlooper might just be the luckiest Democrat this year.

Third District – The Republican primary is a fight between conservative Scott Tipton and ultra-conservative Robert McConnell. Tipton has raised nearly twice as much money as McConnell, but McConnell may benefit from an endorsement by Sarah Palin. The winner tonight takes on incumbent Democrat John Salazar.

Seventh District – Ryan Frazier has a huge 4:1 money advantage over Lang Sias in the GOP primary. The winner takes on incumbent Democrat Ed Perlmutter in this Democratic leaning district.

Connecticut

Governor – There are contested primaries in both parties for this open seat. On the Democratic side, Ned Lamont, best known for defeating Joe Lieberman in the 2006 Democratic primary for Senate, and Stamford Mayor Dan Malloy are extremely close. The latest poll has Lamont with a three-point lead.

On the Republican side, convention-endorsed Tom Foley has long been the front runner.  Foley still has an eight point lead over Lieutenant Governor Mike Fedele in the latest Quinnipiac poll, but the poll found a large final surge for Fedele and a large number of undecided voters. If this trend continues, Fedele might pull off the win. Oz Griebel is also in the race, polling a strong third.

Senate – Polling indicates that self-financed millionaire Linda McMahon is set to  win the Republican primary easily against Rob Simmons and Peter Schiff. Having a fortune to spend in a contested primary can pay off.

Fifth District – There is a three way GOP primary in the Connecticut 5th district featuring Mark Greenberg, Sam Caligiuri, and Justin Bernier. Caligiuri won the party’s endorsement at the state convention. The winner takes on incumbent Democrat Chris Murphy, who is probably favored to win in November.

Georgia Runoff

Governor – The big race here is the governor primary runoff between Republicans Karen Handel and former Representative Nathan Deal. In the first round, Handel had 34.1 percent of the votes and Deal had 22.9 percent. A recent poll by InsiderAdvantage had the race tied 46 percent-46 percent while a recent Mason-Dixon poll found Handel leading 47 percent to Deal 42 percent. Primary runoffs tend to very low turnout elections, making them very difficult to poll accurately.

Seventh District – In this deep red district, there is a runoff between Republicans Rob Woodall and Jody Hice. Woodall recieved 36.3 percent of the votes in the first round while Hice came in second with 26.3 percent. The winner tonight is almost assured to go on to win in the general election.

Ninth District – The great repeated battle between Republicans Tom Graves and Lee Hawkins will probably come to an end tonight. When Nathan Deal resigned to run for governor, he created a special election soon followed by the official primary. Tonight is the fourth time these two have been in an election against each other in only a few months. Incumbent Graves is the huge favorite. He received 49.5 percent in the first round and Hawkins got only 26.7 percent.

Twelfth District – The winner of this GOP runoff with go on to face incumbent Democrat John Barrow. Ray McKinney took 42.6 percent in the first round compared to Carl Smith who got 27.9 percent.

Minnesota

Governor – Tim Pawlenty’s retirement has created potential opportunity for for the Democratic-Farmer-Labor Party. In the DFL primary, former US Senator Mark Dayton seems to have steadily increased his lead and is now the clear favorite. The latest SurveyUSA poll has him with 43 percent compared to Margaret Kelliher at 27 percent and Matt Entenza at 22 percent.