Sen. Mary Landrieu of Louisiana, Sen. Mark Pryor of Arkansas and Sen. Kay Hagan of North Carolina will face voters in 2014 for the first time since Democrats, who in 2010 held majorities in both houses of Congress, pushed through the sweeping legislation popularly known as Obamacare.

That bill helped Republicans win control of the House of Representatives later in 2010, but the GOP was unable to improve on that success in 2012, when Obama won a second term by a sizable margin, and Democrats retained control of the Senate.

The 2014 elections, with more provisions of Obamacare having taken effect, may be a tiebreaker vote on public support for the program. Southern Democrats up for re-election have decided to embrace their 2010 vote, according to The Associated Press.

Some say they will use their office to help constituents understand and use the new medical rules, while looking to fix anything that doesn’t work. Senators like Landrieu also have sharply criticized Republican state leaders like Louisiana Gov. Bobby Jindal, who has opposed the expansion of Medicaid.

Democrats note that under Obamacare, insurers cannot deny coverage because of existing health problems, and some workers who change jobs should have an easier time finding insurance due to state exchanges. They believe policies like that will resonate with voters.

That assumes the policies work. Republicans, who have opposed Obamacare from the beginning, are betting that they won’t. They note that Mitt Romney won Louisiana, Arkansas and North Carolina last year, and the party is optimistic about their senatorial chances in 2014.

Obamacare, therefore, should continue to provide plenty of news in both the medical and political fields over the coming year.