4 weeks to Election Day - Senate

With four weeks until Election Day, the outlook is no clearer in the U.S. Senate, as Republicans remain slight favorites to take control of that legislative chamber, but some of the closer races could go either way in the final weeks campaigning - and it might not be final for weeks after November 4.

The calculus really hasn't changed on three seats that seem to be almost automatic GOP pickups, as Republicans are heavily favored to grab Democratic seats in West Virginia, South Dakota and Montana.

That puts Republicans halfway to their goal of a net gain of six seats to take charge in the U.S. Senate.

Will the GOP get those other three seats? Or can the Democrats hold on, even with a 50-50 split and a tie-breaking vote from the Vice President.

Here's a quick rundown on where some of those close U.S. Senate races stand:

ALASKA - Sen. Mark Begich (D-AK) is clearly in the fight of his life for re-election, as polls have show Republican Dan Sullivan edging ahead in the last few polls. But remember, polling in Alaska is often difficult; six years ago, polling suggested a big win for Begich, but then he won narrowly by just over one percent. If the race is close, it could take a few weeks to count all the votes.

ARKANSAS - This is another prime pickup opportunity for Republicans, where Rep. Tom Cotton (R-AR) has led in most recent polls over Sen. Mark Pryor (D-AR). Pryor brought in President Bill Clinton on Monday to help with his re-election campaign:

Even with Bill Clinton's help, Republicans still think the Natural State will flip to the GOP in this Senate race come November. It's an important part of this November's battleground.

COLORADO - Many Democrats didn't think the seat of Sen. Mark Udall (D-CO) would really be in play this November - but it is. Rep. Cory Gardner has the slightest of leads in the poll averages, but depending on which firm is doing the polling, both candidates have shown a small advantage. President Obama's bad poll numbers seem to have weighed down Udall in this race - but will Udall really lose?

GEORGIA - Democrats still hope that Michelle Nunn, the daughter of ex-Sen. Sam Nunn (D-GA) can bring this state to the Blue column. But the polls have indicated an edge for Republican businessman David Perdue - though he might not be able to get to 50%, which would mean a rare general election runoff for U.S. Senate. That election would not occur until January 6, 2015.

IOWA - It was just a few weeks ago that Democrats were very bullish on this race, but recent polling has indicated a shift that favors Republican Joni Ernst over Rep. Bruce Braley (D-IA). Braley was in Los Angeles on Monday to raise money with Vice President Biden, as the GOP has rushed resources in to help Ernst in the Hawkeye State as well. This seat could be the key to Republicans winning control of the U.S. Senate.

KANSAS - After Sen. Pat Roberts (R-KS) won his GOP primary by a less than stellar margin, he seemed to be ready to coast to re-election. But then, Democrats pulled their candidate out of the race, and shifted their support to Independent Greg Orman; Orman has led a number of recent polls, even though he has refused to say which party he would align himself with in the U.S. Senate. This race only adds to the suspense in the fight for control of the Senate.

KENTUCKY - Conventional wisdom in recent weeks has been that Senate Republican Leader Mitch McConnell is in charge of this race, though a new poll out on Tuesday by SurveyUSA showed Alison Lundergan Grimes (D) suddenly ahead by 2 points. It's the first poll since June that has Grimes ahead in this race, causing some to wonder whether this is an outlier.

LOUISIANA - Because of Louisiana's "Jungle Primary," it seems unlikely that any candidate will get the needed 50% on November 4, meaning this race will likely to go a runoff on December 6. And if the GOP needs just one seat to take charge of the Senate, you can only imagine the amount of money that will be poured into the Bayou State by both parties if this election goes into overtime.

NEW HAMPSHIRE - While a lot of people keep talking up this race, the polls have not rallied around either Sen. Jeanne Shaheen (D-NH) or her challenger, ex-Sen. Scott Brown (R). Brown has had two polls where he was tied, while Shaheen has had several showing her with leads of 6-10 points. The conventional wisdom in Washington is that Shaheen should win this race - but if she doesn't - then that is a sign of major GOP gains in 2014.

NORTH CAROLINA - The Tar Heel State remains a bright spot for Democrats, as Sen. Kay Hagan (D-NC) has been able to maintain a short lead over Republican State House Speaker Thom Tillis. Looking to change the direction of the race, Tillis this week launched a new ad, trying to directly tie Hagan to President Obama.

A new poll out this week showed Hagan up 44-40, with a Libertarian candidate getting 7 percent. That third party number - and the number of undecideds seems high.

The handicappers still believe this year favors the Republicans - but it's still not clear if they will get over the hump to a net gain of six seats.

Four weeks to go.