In a year with a few contenders, Arkansas Sen. Mark Pryor is widely considered the most vulnerable Democrat up for re-election. For Republicans, his seat is a must-win for the party to recapture the Senate majority.

With the president’s job approval rating dropping and southern Democrats disappearing from the congressional ranks, Pryor’s successful bid for a third term would be the ultimate proof that Senate elections are truly a choice between the two candidates on the ballot and the quality of the campaigns.

First elected in 2002, Pryor remains as the last Democrat from a congressional delegation filled with them just a few years ago. With the unpopularity of the president in Arkansas and Pryor’s vote in favor of the president’s health care overhaul law, Republicans believe they have a good shot at a clean sweep in the state’s federal races next November thanks to freshman Rep. Tom Cotton’s candidacy.

Republicans are further encouraged by the fact that Cotton faces no primary competition. He’s the rare GOP Senate candidate to have the support of both the establishment and tea party wings of the party — and therefore a clear shot at a Democratic incumbent. Meanwhile, Democrats, who see a path to victory, have already begun branding Pryor’s GOP competition as a “reckless and irresponsible” alternative to the incumbent.

In terms of total spending, Pryor was one of the top targets of outside groups on TV in 2013 and should be near the top by November. To combat that, the Pryor campaign spent the most by far on TV among his fellow endangered Democratic incumbents. Pryor’s first ads highlighted his Christianity and support for gun rights — an effort to solidify his independent bonafides in preparation for the onslaught of ads tying him to Barack Obama.

The race is rated Tossup/Tilt-Republican by Rothenberg Political Report/Roll Call.

Editor’s note: Not all congressional races are created equal, and Roll Call’s politics desk admits to playing favorites. So in the spirit of the holidays, these are a few of our favorite things (races) to cover this cycle. We’re shining a spotlight on our 12 most fascinating races through the new year — in no particular order. Happy holidays from @RollCallPols!

Check out the rest of Roll Call’s most  fascinating races of 2014: California’s 31st District, California’s 17th District, Illinois’ 13th District, West Virginia’s 2nd District,  Arizona’s 2nd District,

Mississippi Senate and Alaska Senate.