Updated

Senate races in the America West could provide the Republican Party what it needs to gain the majority in the U.S. Senate in 2012. According to many prognosticators, including Fox News' own Chris Stirewalt, nearly half the most vulnerable seats currently held by Democrats are in the Rocky Mountain West.

They include the seat held by first term Democratic Senator John Tester of Montana, whose margin of victory in 2006 was tighter than his buzz-cut hair and likely had as much to do with his opponent. Three-term incumbent Republican Senator Conrad Burns' associations with corrupt lobbyist Jack Abramoff likely had as much to do with Tester's win as the latter's appeal to voters. Burns was the longest running Republican Senator in Montana history, and the only one to be elected since 1913.

Many outside the West see Montana as a conservative bastion, which it is in the eastern two-thirds of the state. But the smaller, more populated western third of the state is heavily Democratic.

But even Democrats in the Intermountain West tend to be very independent and Tester's vote in favor of Healthcare Reform will be hard, if not impossible for him to defend if he decides to seek reelection.

Support for Healthcare reform could also sink any reelection effort by Nebraska Democrat Ben Nelson. Nelson carried 42 percent of the Republican vote when he won election to his second term in 2006, more than any other Democrat in the nation. He also won the 73 percent of Independents, crucial in any state-wide election in the region.

But like the rest of the nation, Independents out West swung right in the 2010 mid-terms making Nelson one of the most vulnerable Democrats in the Senate.

The retirement announcements of North Dakota's Kent Conrad and New Mexico's Jeff Bingaman have swung the door wide open for the GOP to take two more Senate seats in the West in 2012.

North Dakota's lone Congressional Representative Earl Pomeroy, a Democrat who held the seat since 1992, was beaten badly in November by Republican Rick Berg. Berg is the first Republican in 24 years to hold the state's at-large seat. North Dakota's other Democratic Senator, Byron Dorgan, opted not to run for reelection to the seat he had also held since 1992. That seat was won by the state's former Republican Governor, now U.S. Senator John Hoeven, by 54 percentage points. If ever there is such a thing as a sure win for the GOP in 2012, Conrad's Senate seat is as close to a sure win for the GOP in 2012 as any other in the nation.

Bingaman was deemed fairly safe until he decided to call an end to what will end up being a 30 year career in the U.S. Senate. While not a sure thing for the GOP, the race for this seat is at best a tossup. Nearly every Republican member of the State Legislature has been floated as a potential candidate, and several have expressed interest.

Success in these four Western states alone could give the GOP the Senate majority they craved but failed to achieve in 2010.