President Obama sees 2014 as a “breakthrough year” for his agenda, but a number of unresolved challenges threaten to undermine his bid to turn the corner on the worst stretch of his presidency.

Whether the president can fix glaring problems with Obamacare -- and sell the merits of his signature domestic initiative to a disillusioned public -- will determine whether the annus horribilis of 2013 was an aberration.

Obama must also kick-start stalled legislative goals, navigate shaky political terrain for vulnerable Democrats ahead of midterm elections and stem a growing tide of instability across the Middle East.

Here are five of Obama's highest priorities for the new year:

1. Stop the Obamacare bleeding: New year, same problem. The president failed to reassure Democrats or sway skeptics of his health law with the botched Obamacare rollout.

The administration also is well behind in its goal of enrolling 7 million Americans in Obamacare by the end of March, when penalties on the uninsured kick in. Supporters and critics agree: March 31 is the most important date in Obama’s second term.

“The real key on enrollment is the net number of people with health insurance,” said Dennis Smith, former health services secretary under Wisconsin Gov. Scott Walker. “We could actually end up with fewer people with insurance. That clearly would be a devastating blow.”

White House claims of fully functional online marketplaces will be tested as consumers begin using their Obamacare coverage. The verdict on the plan will emerge as many consumers deal with higher premiums and deductibles, as well as limitations in access to doctors and hospitals.

2. Limit the political blowback for Democrats: The president and congressional Democrats suffered a sharp drop in their approval ratings during the withering focus on Obamacare.

Obama watched the GOP take over the House in 2010 in large part because of the health care debate. Republicans, who were on the defensive after the 16-day government shutdown, now see a prime opportunity to hold the House and take back the Senate.

Progressive consultants say Democrats should own up to the health law's initial shortcomings and tout Obamacare's more popular provisions.

“Democrats cannot run from Obamacare,” said Democratic strategist Christopher Hahn, a former aide for Sen. Chuck Schumer, D-N.Y. “If they try to distance themselves from it, it's going to kill them.”

3. Seize the high ground in the National Security Agency debate: Few issues unite libertarian-leaning Republicans and progressive Democrats more than opposition to NSA surveillance practices.

The administration defends those programs as legal, but the leaks by former government contractor Edward Snowden have taken a toll on perceptions of Obama's trustworthiness.

The NSA uproar also diminished Obama’s one-time rock star status abroad and led to public criticism from foreign leaders.

The president is reviewing recommendations from an outside panel and hinted that he is open to new restrictions.

If Obama's changes are seen as too modest, however, he risks alienating Democrats and the influential tech industry. A sweeping overhaul though could anger national security hawks.

4. Get immigration reform across the finish line: Obama put comprehensive immigration reform at the top of his 2014 wish list. House Republicans stand in the way.

Speaker John Boehner, R-Ohio, has signaled a willingness to tackle the issue through a piecemeal approach. The president must be careful to allow Boehner to rally conservative support and not anger the GOP base.

“We’re not stupid,” one House GOP leadership aide told the Washington Examiner. “We understand the political ramifications if we ignore immigration altogether. But if Obamacare taught us anything, it’s that you shouldn’t pursue some massive piece of legislation because of political pressures — we’ll do this at our own speed.”

5. Manage simmering foreign conflicts: In 2013, Obama helped engineer a short-term nuclear deal with Iran and an accord to eliminate Syrian strongman Bashar Assad's chemical weapons.

Now he must ensure that Iran follows through on its commitments and drive a hard bargain in any further negotiations. Staunch resistance on Capitol Hill and abroad to the deal leaves him little room for error.

Syria missed a key Dec. 31 deadline for dismantling its chemical arsenal, and critics say the vaunted deal only helped Assad maintain his grip on power.

Mideast volatility after the Arab Spring and increasing violence in Iraq and Afghanistan could also overtake Obama's foreign policy agenda.

Afghan President Hamid Karzai, meanwhile, is also refusing to sign a postwar security pact. With Afghan elections and the U.S. withdrawal date nearing, Obama has little time to salvage the decade-long American mission in Afghanistan.