chosen by National Journal as likely to flip, Republicans are hoping to make the switch happen.

The 12th district stretches from East St. Louis in the west -- with a chunk removed in the middle -- to the confluence of the Mississippi and Ohio Rivers in the south. The district leans Democrat, is largely agricultural, but might be leaving its incumbent vulnerable.

The incumbent is Democrat Bill Enyart, a Belleville lawyer and former Adjutant General of the Illinois National Guard. A first-time candidate in 2012, Enyart won over 50% of the vote despite a Green Party candidate receiving over five percent.

After going with an occasionally under-performing lumber business scion, 30-year-old Jason Plummer, in 2012, Republicans are counting on State Representative and Republican Mike Bost of Murphysboro.

Bost, a former firefighter and veteran of the U.S. Marines, is perhaps best known for a pair of tirades on the floor of the General Assembly. One of them earned him the runner-up spot on CNN's list of "Celebrity Flip-Outs."

saying, "I thought I was going to be No. 1" on the list.

Antics aside, Bost is a more seasoned politician than Plummer, winning his first election to the Illinois House of Representatives in 1994. Bost says he is seeking the seat to fight for jobs, against over-regulation, and a solution for immigration.

In his first term, Enyart has not caused much controversy and has voted with his party almost 90 percent of the time. One of his bills, which is designed to improve job training skills -- the JOBS Act -- has attracted only one cosponsor. However, a memo from the National Republican Senatorial Committee (NRSC) last November showed that the incumbent had only a 25 percent approval rating in his district.

In an otherwise economically-depressed region, the biggest employer in the district is Scott Air Force Base in Shiloh. Each candidate has made the base a part of the campaign. Enyart said on Bost's announcement:

"The people of Southern Illinois sent me to Congress to fight for jobs, protect Medicare and Social Security, and ensure the future of Scott Air Force Base."

Bost alluded to military spending, and by implication Scott, in his announcement last summer:

"I was around when (former president) Jimmy Carter cut the military. That's why we failed to save the hostages in Iran. . . . We were using equipment at that time we had left over from Vietnam."

National politics, such as the ineffective introduction of the Affordable Care Act (ACA), will likely play a part in the election. If Bost is thought to have a reasonable chance to unseat Enyart, money from national groups may pour into the race. Although a supporter of the health care plan, Enyart voted in 2013 for a one year delay in the implementation of the ACA.

showed the Republican leading Enyart 33-27 -- leaving over 40 percent undecided. A potential wildcard in the race is Paul Bradshaw, the Green Party candidate, who took a full 5 percent of the vote in 2012.

One factor that may play into Enyart's favor is that his base is in the Metro East area, the most populous region of the district, while Bost, who is from the much less populated south, has to introduce himself to the larger electorate. However, as John Jackson of the Paul Simon Public Policy Institute points out, 2014 may be a better year than others because, "The party that controls the White House almost always loses seats in the House in the off-year elections."

Republican Mike Bost may need that trend to hold up to pull off the victory. In a district that only voted for President Obama's re-election by a margin of 1.5 percentage points, Bost may have a chance.