The class of senators swept into office riding Barack Obama’s coattails in 2008 — giving Democrats a supermajority in the process — now stands to be the party’s majority firewall when it faces voters in 2014.

Once the building blocks to a supermajority, the first-term class of 2008 Democratic senators now finds itself as the cornerstone of a five-seat majority in danger of crumbling. First elected on the same ticket as President Barack Obama, their next fight carries inherent risks and disadvantages.

This cycle, there are more than enough seats in play for Senate Democrats to lose the majority. But party aides remain confident in their eight first-term Democrats up for re-election — all of whom won GOP seats six years ago.

Some in the class, such as Alaska Sen. Mark Begich and North Carolina Sen. Kay Hagan — the only two from states that the president lost in 2012 — are more vulnerable than others.

But all of them are no longer running with an Obama wind at their backs — or against an unpopular war in Iraq and outgoing President George W. Bush.

With the benefit of a wave cycle, this class defeated five Republican incumbents and picked up three other GOP-held open seats. Today, Democratic strategists described this particular group of senators as in remarkably good shape for 2014.

“They’re each in their own way dragon slayers because of the kind of people they defeated,” said Martha McKenna, political director at the Democratic Senatorial Campaign Committee in 2008. “It’s not to say that these aren’t going to be tough races, but I think each of these people have been working just as hard as senators as they worked in their campaigns.”

Along with Begich and Hagan, the class includes Sens. Al Franken of Minnesota, Jeanne Shaheen of New Hampshire, Mark Udall of Colorado, Tom Udall of New Mexico, Jeff Merkley of Oregon and Mark Warner of Virginia.

The eight boast similar traits, even if their politics differ. Notably, they have mostly kept their heads down and mouths shut in the Senate.

But they do not enter the 2014 cycle on equal footing. Along with their personalities, their success will be based in part on what they’ve done over the course of their terms and how closely they match the ideological center of their respective states.

“Obviously, running in a midterm will be tougher for Democrat incumbents than running in the blustery political tailwind they enjoyed in 2008,” said Scott Bensing, executive director at the National Republican Senatorial Committee in 2008. “They are now running in an Obama economy … and don’t have the luxury of running against George W. Bush, which sadly was all most Democrat Senate candidates needed in 2006 and 2008.”

It’s still early in the cycle, but only a few challengers have emerged to take on this class. Democrats may be in trouble if several of these races look more competitive down the road than they do now.

Given their states’ unpredictable political dynamics, Franken and Shaheen could be in for competitive races depending on who steps up to challenge them. Franken defeated Republican incumbent Norm Coleman in 2008 by 312 votes in the smallest Senate race margin in the country. Shaheen defeated then-Sen. John E. Sununu by 7 points in the swingy Granite State.

But so far, no top-tier Republicans have proactively looked into running against either senator.

The Udalls, Merkley and Warner remain ranked as the least vulnerable of the lot. They may not have changed in the past six years, but the political demography of their states has.

Ten years ago, Democrats passed over Mark Udall for Senate because they viewed him as too liberal for a statewide bid in Colorado. The state has moved to the left, exemplified by its vote to legalize marijuana last November.

His cousin, Tom Udall, who won by 22 points in 2008, hails from a state with a booming Hispanic population that, as a result, finally fell off the GOP’s map last cycle.

It’s hard to see Merkley, who defeated GOP Sen. Gordon H. Smith by 3 points in 2008, losing in a state as Democratic as Oregon. Meanwhile, Virginia Republicans aren’t publicly broaching the subject yet of how to take on Warner, the most popular politician in a state that’s increasingly voted for Democrats in recent cycles.

Defense will be a priority for Democrats this cycle, with seven seats up in states that the president lost and with few offensive opportunities. At this point, Democrats appear to have a chance to pick up just two Republican seats — in Georgia and Kentucky, both of which Obama lost handily.

With that, holding all or most of the seats the party won in 2008 is vital.

“It’s going to be a tough economy that they’re running in, and the national agenda is not always going to be the best for them,” Democratic pollster Celinda Lake said. “I think they knew that coming in, and I think they’ve been prepared for it for a while.”

Democrats hope the incumbents running in the toughest states are able to follow the example of people such as Montana Sen. Jon Tester, who won re-election last year in a state Obama lost by double digits.

“It’s still going to be a hard fight, but with each one of these guys, I could make a legitimate argument,” Democratic pollster Jef Pollock said. “Begich and Hagan are for sure the toughest, but I like where they sit right now.”