WASHINGTON — It would be hard to imagine a more dispiriting prelude to a new presidential term than this week’s sorry “fiscal cliff” deal to defer (and perhaps multiply) the nation’s financial problems. After President Obama failed to negotiate a serious “grand bargain,” he had to be rescued with a mini-bargain brokered by Vice President Joe Biden, the loquacious master of old-time, cracker barrel politics.

Obama had seemed poised a few weeks ago to become at last the political leader the country needs. He won a brilliant election victory, using political tools so sophisticated that Republican strategists have been trying ever since to “reverse engineer” them so they can avoid humiliating defeats. Obama spoke to the nation after the tragedy at Sandy Hook Elementary School in a voice that was truly presidential in its restrained expression of deep grief. In short, Obama seemed ready to lead.

And then what happened? In his December fiscal cliff negotiations with the GOP, Obama repeated many of the mistakes he made earlier in his first term. Rather than come to the table with a grand vision of his own — a real strategy for cutting the deficit and the entitlement programs that drive it — he played a poker game of incremental bargaining with House Speaker John Boehner. This was an unwise approach even before Boehner demonstrated his incompetence by failing to pass his “Plan B” alternative through the GOP-controlled House.

Unfortunately, Obama has been playing a waiting game on fiscal issues ever since he became president. He didn’t formulate a plan for long-term solvency partly because he didn’t want to give up the political weapon of Social Security before the 2012 election; he didn’t fully embrace the Simpson-Bowles deficit-reduction plan for the same reason. “Too early,” said his aides. He didn’t talk honestly about the deficit problem during the campaign, either. And although Obama finally offered in last month’s discussions with Boehner to revise the cost-of-living adjustment to Social Security, he retreated after the Plan B debacle.

Let’s assume it was tactically smart for Obama to play politics with the deficit issue through the campaign. Having won, Obama should quickly have taken the high ground and urged the fiscal reforms that every thoughtful member of his team knows are necessary. Instead, he chose the small-bore approach of continuing to insist, ad nauseam, on his campaign pledge that tax rates had to go up for the wealthiest Americans. OK, he got that. Now what?

Obama has been backing into the second term in his Cabinet choices, too. He had a long time to ponder whom he wanted on his national-security team, for example. But the White House adopted a trial-balloon approach for its apparent first choices, U.N. Ambassador Susan Rice at State and former Sen. Chuck Hagel at Defense. Critics began attacking, with the result that Rice backed out and Hagel has taken so much flak that he deserves another Purple Heart. These are unnecessary, self-inflicted wounds for the administration.

It’s important for America’s global standing that Obama, having been re-elected, achieve a successful second term in which he is seen to be solving the country’s major problems. He’s likely to have the advantage, these next four years, of an improving U.S. economy. But he has to avoid the mistakes that undermined his first term. Specifically:

— Obama must lead his own party, as a first step toward truly leading the country. The top Democrats in Congress, Sen. Harry Reid and Rep. Nancy Pelosi, come across to much of the country as partisan, divisive figures. Yet too often, Obama defers to them. Using Biden as the political Mr. Fix-It only compounds this problem. Biden may be a dealmaker, but he’s hardly a visionary. It’s Obama’s job to lead the party toward entitlement reforms and other policies that will be painful but necessary.

— Obama should champion a clear plan for fiscal reform. Last month, he played Let’s Make a Deal, showing his cards only when the other side made concessions. He’s president, not Monty Hall.

— Obama should communicate his vision forcefully to the country, governing over Congress’ head as Ronald Reagan did, if necessary.

It’s depressing that after four years of gridlock, a president who won what was supposed to be a decisive election is back once again to the politics of gridlock. That’s bad for Obama, but worse for the country. Obama can still be the strong, successful president the country needs — but not unless he lifts his game.

David Ignatius is a Washington Post columnist. His email address is davidignatius@washpost.com.