President Obama’s narrow victory has left proponents of the Affordable Care Act (ACA) breathing a collective sigh of relief, believing that the legislation is safe. It’s true, of course, that the election’s outcome has ended the prospect of a new administration using Republican majorities in both chambers and the budget reconciliation process to force outright repeal. But the reality of the economic and political situation means the core elements of the ACA remain very much in play.

The primary reasons for this are the continuing problems with the federal budget deficit and the national debt and the worrying long-term weakness of the economy. Add to that the increasing skepticism that the ACA’s blunt tools will slow costs.

Let’s remember that the most important provisions of the ACA, such as penalties for Americans lacking insurance and firms not offering it, the expansion of Medicaid, and the heavily subsidized exchange-based coverage, do not go into effect until 2014. Meanwhile, new taxes on self-employment and limits on flexible spending accounts are scheduled to go into effect next year, just as Congress will be trying to boost employment growth. Additionally, lawmakers will be desperately searching for ways to delay or cut spending to deal with the deficit. That adds up to 2013 being a year for buyer’s remorse in Congress and around the country.

The reaction of employers to the ACA is likely to be the first pressure point for changes in the ACA or at least the suspension of some of its provisions. Employers have been reporting for some time that concerns about mandatory benefits are slowing their hiring. And as the Wall Street Journal recently reported, lower-wage employers are moving towards hiring part-time employees to avoid the ACA’s penalties. These patterns will only grow in 2013 as many employers eye the prospect of putting their employees into the heavily subsidized exchange plans. And the possibility of larger-than-expected enrollment in health insurance exchanges will sharply increase the budget costs, adding to the deficit pressures to curb the ACA.