Congratulations are owed to President Obama. He’s still The Decider. After taking a moment to savor a well-earned victory, he’ll have to roll up his sleeves. An agenda packed with formidable challenges awaits resolution.

The message of this election is that voters are sick of gridlock and extreme partisanship.

For Mr. Obama, this means a readjustment of relations with Congress. Members of Congress like to be courted, but they’ve felt ignored by the president. He vowed to fight harder in his second term by taking his issues to the country. Fine, but lawmakers have the power to make or break a presidency. Successful presidents work The Hill like a pol works a key precinct.

Republicans in Congress have a similar duty to change course. They lost ground in the House, and they not only failed to win the Senate, which they had a fair chance of capturing, but they fell further behind. The GOP brand has lost some of its luster, thanks to its obstructionist label. It’s time to rebrand.

Good start: Majority Leader John Boehner said he called President Obama on Wednesday to offer this message: “The Republican majority stands ready to work with you.” He went on to make the argument against tax cuts (here we go again), but he also said he read the election results as a mandate from the American people “to work together.” Let’s hope he means it.

Not so good start: In the Senate, Republican Minority Leader Mitch McConnell has become the personification of obstructionism. In contrast to the graceful concession statement offered by Mitt Romney, the Kentucky senator managed to strike a sour note. “The voters have not endorsed the failures or excesses of the president’s first term, they have simply given him more time to finish the job they asked him to do.”

That won’t sit well with Americans yearning for an end to gridlock. It won’t win the party new friends, nor will that pugnacious attitude win big elections. Voters aren’t asking Sen. McConnell or like-minded Republicans to roll over, but rather to meet the president halfway.

Now about the agenda itself:

• Avoid the looming “fiscal cliff” at the end of the year by making a short-term deal. This will require a compromise in the upcoming lame-duck session of Congress to extend the status quo until next year but squelch draconian spending cuts and tax increases that could send the economy into a tailspin. After that, the president has to make good on his second-term promise to put government on a path to cutting deficits by $4 trillion in 10 years. The president should embrace the ideas of his own, bipartisan deficit reduction committee and lead the way to a sensible, long-term compromise agreement.

• Immigration. This an unfulfilled 2008 promise: achieve an immigration overhaul that sets a path to citizenship for undocumented immigrants under certain conditions. The Latino vote made a difference in this election. The GOP should get the message that the changing face of America makes intransigence on immigration reform a losing proposition.

• Climate change is for real. From ground-water seepage and contamination in Miami to damage from rising seas in Manhattan, the evidence is apparent and undeniable. The president largely ignored this in his first term, but he has to lead on this issue in the next four years.

The president fought for a second term. He earned one. Now he has to show Americans that they made the right choice.