Both candidates for president failed to tell the truth about the biggest issues facing the country: spending, taxes and deficits.

Every reasonable and realistic person in Washington — and, yes, there are some left — knows that any “grand bargain” must involve both higher revenues and reduced benefits. But since those options are unpopular, both candidates hid behind frothy and fraudulent promises that no real sacrifice would be required — at least by their own party’s core constituents.

President Barack Obama essentially said that soaking the rich would solve the problem. Republican Mitt Romney said that lowering taxes and cutting regulation would magically create new profits and comfortable surpluses. They were both dissembling, and they both knew it.

But that was during the campaign, when both men were scrambling for votes in an extremely close election. Now that the election is over, it’s time to get serious. It’s time to take risks and say unpopular things. It’s time for leadership.

Of course, that’s easy to say and hard to do. Gridlock is a more likely outcome than progress. Ideologues on both sides are digging in for trench warfare and sending out signals that any hint of compromise will be met by immediate cries of betrayal.

Those ideologues have dominated the capital over the last few years, but they should not win again. The national interest demands a drive for common ground. And so do many voters. “Tonight you voted for action,” the president said Tuesday in his acceptance speech, “not politics as usual.”

That’s right, and the president has to take the lead here. Yes, he promised four years ago to govern in a bipartisan way, and no, he did not succeed in doing that. The bulk of the blame rests with Republicans who blocked him at every turn, but there’s no point in refighting those old battles. The time for finger-pointing is over. It’s a new day, a new term. The president actually urged voters to support “anybody, of any party” who would “break the gridlock in Congress,” and now he has to govern by supporting those same people.

For starters, he has to put on the table significant entitlement reform — raising the eligibility age for Medicare, for example, or slowing the rise of Social Security benefits. And he has to stand up to the liberal purists who insist that no benefit — not one — should be part of any discussion.

A recent headline in Politico signaled what he’s up against: “Liberals fear grand bargain betrayal if Obama wins.” Van Jones, a former Obama aide, sounded their battle cry: “There is no reason in the world why the pillars of middle-class security, the earned benefits our parents fought for, should be on the chopping block.”

Actually, there is a reason, a good one: We cannot afford all those benefits, particularly as the baby boomers retire and swallow a growing chunk of the annual budget. And Obama seems to understand that.

“It will probably be messy. It won’t be pleasant,” he told the Des Moines Register. “But I am absolutely confident that we can get what is the equivalent of the grand bargain that essentially I’ve been offering to the Republicans for a very long time, which is $2.50 worth of program cuts for every dollar in (taxes), and work to reduce the costs of our health-care programs.”

But the president needs a negotiating partner, and Republican leaders like House Speaker John Boehner and Senate Minority Leader Mitch McConnell also have to show some courage. They have to take on the purists in their own party who insist that not a dime of new taxes — not one — can be part of any “grand bargain.” Those leaders were determined, in McConnell’s famous words, to make Obama a “one-term president,” and they flinched from any deal that would burnish the president’s re-election credentials.

But that argument is over. They lost. Now, like the president, they have to forget old grudges. They have to take a deep breath and a second look. And there are a few brave souls in their party who are willing to speak the unspeakable: New taxes have to be part of any deal. One of them, Sen. Saxby Chambliss of Georgia, recently warned a business group in New York: “If you like the package that we ultimately come up with, then we haven’t done our job — because everybody is going to ultimately pay a price in this.”

That’s true. And it’s time for truth.

(Steve and Cokie Roberts can be contacted by email at stevecokie@gmail.com)