WASHINGTON – President Obama’s victory eliminated the last serious threat to the existence of his health-care law, but it didn’t remove an array of challenges that will ultimately determine whether the 2010 statute is a policy triumph or a disappointing muddle.

Among the tasks Obama officials still face: protecting the law from budget cuts Republicans are sure to demand during upcoming negotiations, wrangling wary governors into going along with the law’s expansion of Medicaid, and ensuring that the private insurance markets, or “exchanges,” at the heart of the law can be rolled out by the law’s 2014 deadline.

An early indicator of whether the implementation will be choppy could come Nov. 16, when states must declare whether they intend to manage their exchanges on their own, cede full control to the federal government or enter into some form of federal-state partnership.

The exchanges are supposed to make it easier and more transparent for small businesses and millions of individuals who are not covered through employers to shop for health insurance.

Many of these individuals will be eligible for federal subsidies to buy private coverage.

So far, only 13 states have officially said they will set up exchanges. Republican governors in about a dozen states have held off giving their answer for months — first in anticipation of the Supreme Court’s ruling, and then, after the court upheld the law, in the hope that Mitt Romney would win the presidential election and make good on his promise to repeal it.