With President Barack Obama at the helm for four more years and a strengthened Democratic majority in the Senate, and with the Republicans decidedly in control of the House of Representatives, both sides may now feel emboldened to pursue their party's preferences.Rarely has it been this clear, however, that elected leaders need to come together to address our nation's rising federal debt.Important decisions need to be made in the next two months to address the "fiscal cliff." Both sides will have to come together in the spirit of good governance to replace the abrupt and mindless spending cuts and tax increases set to take effect Jan. 1 with a gradual and intelligent deficit reduction plan.Many partisans on both sides seem to think they have the upper hand. Democrats see the threat of large defense cuts and massive tax increases as a way to force tax increases for the rich.Republicans see large domestic spending cuts, tax increases on poor and middle-income Americans, and the need to increase the debt ceiling as their own leverage points.There has even been talk of going over the fiscal cliff to potentially strengthen each side's bargaining position. Going over the cliff, though, would mean betting the country on the hope that the other side will back down before it is too late. That's a bet we shouldn't take.Going over the fiscal cliff would mean allowing a massive and immediate cut to nearly every major government agency and activity, including those vital to our national security or economic growth. It would mean a large and immediate tax increase on nearly all Americans, not just the highest earners. It would mean a double-dip recession at a time when the economy is still weak and many Americans are struggling to find work.Simply punting on the fiscal cliff and continuing to add to the debt would be an even bigger mistake. It would show markets we cannot put our financial house in order. Instead of using this moment as leverage to score political points, our elected leaders should seize the opportunity to finally address the long-term imbalance between government spending and revenue and to prevent a future debt-induced economic crisis.What does that alternative look like? We already have the blueprints.It's the type of bipartisan package toward which the fiscal commission I co-chaired with former Sen. Alan Simpson, the Domenici-Rivlin group, the Senate's "Gang of Six" and the Obama-Boehner negotiations all worked. It's a package large enough to put the debt on a clear downward path, relative to the economy, and designed well enough to promote, rather than disrupt, economic growth.It's a package that includes real spending cuts and structural entitlement reforms to make Social Security solvent yet slows the growth of federal health spending while protecting vulnerable populations. And it's a package that institutes fundamental tax reform and encourages economic growth by cutting spending in the tax code to reduce rates and generate additional revenue for deficit reduction.Most important, it's a package that can get bipartisan agreement. While there will undoubtedly be many honest disagreements about the specific elements, I believe that both Obama and House Speaker John Boehner are willing to make the type of principled compromise necessary to reach an agreement.Policymakers could agree in the lame-duck session on the basic framework of the deal.Congress could enact a "down payment" of savings from spending and revenue policies, along with a process for achieving the remaining savings by July 4, with enforcement mechanisms to ensure that the promised savings are achieved. Designed appropriately, such a package would be credible enough to allow for a temporary delay of the scheduled sequestration policies and extension of expiring tax cuts.Nearly three years' worth of work has gone into developing the policies and raising awareness on the need for a comprehensive plan. Members of both parties and both houses understand this. So do concerned citizens across the country -- 300,000 of whom have signed a petition at FixTheDebt.org, demanding that Washington act.The only ingredient missing is political will.Erskine Bowles served as chief of staff to President Bill Clinton and was co-chairman of the National Commission on Fiscal Responsibility and Reform.