Democrats and Republicans Walk Fine Line in Senate Races

May 19, 2012 -- Bipartisanship is an outdated concept. It's like booking a vacation through a travel agency or putting a letter in the mail.

Or at least that's what the narrative in Washington would have you believe. Several prominent senators known for their willingness to reach across the aisle -- Olympia Snowe of Maine, Joe Lieberman of Connecticut, Ben Nelson of Nebraska -- have announced this year that they're retiring, fueling talk that compromise has become a lost art inside the Beltway.

But in several top Senate races across the country, the success of candidates in both parties will actually depend on their ability to tow a moderate line, and, in a blunt matter of speaking, distance themselves from their parties' respective presidential candidate.

There are 33 Senate seats up for election this fall, though only about half of them are considered truly competitive. Several of the races will be in states considered safe bets for either Republicans or Democrats in the presidential election. As a result, candidates of the opposite party are forced to walk a political tightrope, distancing themselves from their parties' presidential candidates without alienating their base.

Here is a list of five contested Senate races in states where you likely won't see Mitt Romney or Barack Obama campaigning too much.

MASSACHUSETTS

Mitt Romney may be the former governor of the Bay State, but it's not part of his electoral strategy. Massachusetts is traditionally a solidly blue state, and polling shows Obama with a double-digit lead there over Romney. Nevertheless, the state has one of, if not the most closely watched, Senate races taking place between Republican incumbent Scott Brown and his likely Democratic challenger Elizabeth Warren.

Warren is very much aligned with the administration after she laid the foundation for the consumer financial protection bureau, a government agency created during Obama's first term. With many Democrats likely to turn out for Obama in November, Brown must be careful to avoid alienating Obama supporters, while still drawing a sharp political contrast between himself and his opponent. A great deal of the Brown campaign's narrative has involved highlighting his history of bipartisanship.

INDIANA

The general consensus in D.C. is that the defeat of six-term incumbent Senator Richard Lugar to state treasurer Richard Mourdock in Indiana's Republican primary put the state's senate race on the map for Democrats. Although he narrowly won the state in 2008, Obama's approval ratings are low in Indiana, and ABC News rates the state as solid Republican in the presidential election. With this in mind, the success of Democratic nominee Joe Donnelly, a Democratic Congressman and member of the Blue Dog Coalition, will hinge upon his ability to convince moderate voters that tea-party-funded Mourdock is simply too conservative for the state, and get some crossover voters.

Mourdock has been open about his negative opinions on bipartisanship- telling ABC News that "bipartisanship has taken us to the brink of bankruptcy." Expect Donnelly to try and capitalize on this.

NORTH DAKOTAIn North Dakota, Democratic senator Kent Conrad is retiring, leaving an open race that looks likely to between former Democratic state attorney general Heidi Heitkamp and Republican Congressman Rick Berg. John McCain carried North Dakota in 2008, and ABC News rates the state solid Republican time around as well.

Heitkamp's past support for Obama has already been used against her in the race by outside spending groups. The conservative-aligned group Crossroads GPS ran an ad against Heitkamp highlighting a comment she made in 2008, where she said she thought Barack Obama was going to be "amazing."

MONTANADemocratic senator Jon Tester faces his first re-election campaign this year in a solidly red state. Tester narrowly defeated then incumbent senator Conrad Burns in 2006, and he'll face a tight re-election this year, with polls showing him in a close race with likely Republican candidate Denny Rehberg. Tester will need to court Romney voters in order to carry the race.

HAWAIIIt's likely that no one understands this challenge of distancing oneself from their party's presidential nominee better than likely Republican senate candidate Linda Lingle in Hawaii. The two-term governor is running in a traditional blue state, in a presidential election, where the Democratic nominee is from the state. For Lingle to have a chance of winning the open senate race, she needs Obama/Lingle voters to turn out in good numbers.

Lingle has already begun to draw distinctions between herself and other members of "her own party," penning an article earlier this year about her support for abortion rights.

"It pains me deeply to see members of my own party attempting to legislate women's health and contraception choices," Lingle wrote in the Hawaii Reporter. "Throughout my years of public service, I have listened with great interest to both sides of these often controversial issues. The positions taken were argued with equivalent passion and effectiveness. But I have always been an ardent supporter of women's rights, including a woman's right to choose."