Memo to the Republican Party: You had a great night Tuesday. But remember: You didn’t win it. The Democrats lost it.

This is not to say that you didn’t show discipline in making the election a referendum on six years of Barack Obama. You exercised adult supervision over the choice of candidates. You didn’t allow yourself to go down the byways of gender and other identity politics.

It showed: a gain of probably nine Senate seats, the largest Republican House majority in more than 80 years, and astonishing gubernatorial victories, including Massachusetts, Maryland and Illinois, the bluest of the blue, giving lie to the Democrats’ excuse that they lost because the game was played on Republican turf.

The defeat – “a massacre,” The Economist called it – marks the final collapse of Obamaism, a species of left liberalism so intrusive, so incompetently executed and ultimately so unpopular that it will be seen as a parenthesis in American political history. Notwithstanding Obama’s awkward denials at his next-day news conference, he himself defined the election when he insisted just last month that “these (i.e. his) policies are on the ballot – every single one of them.”

They were, and America spoke. But it was a negative judgment, not an endorsement of the Republican Party. The prize for winning is nothing but the opportunity for Republicans to show that they can govern – the opportunity to seize the national agenda.

Five weeks ago, I suggested a series of initiatives that would be like the 1994 “Contract with America,” but this time post facto. It’s not rocket science. Mitch McConnell, the incoming Senate majority leader, and Speaker John Boehner are already at work producing such an agenda.

It needs to be urgent, determined and relentless. Say, a bill a week for the first 10 weeks. Start with obvious measures with significant Democratic support, like the Keystone XL pipeline.

Like fast-track trade negotiation authority that Harry Reid killed and that Obama, like all presidents, wants. Republicans should propose and pass it, thereby giving Obama a victory and demonstrating both bipartisanship and magnanimity (as well as economic good sense).

Then a simple, targeted bill to repatriate the $2 trillion of assets being held by U.S. corporations overseas, a bill to authorize and expedite the export of liquid natural gas and crude oil (the latter banned by an obsolete 1975 law) and a strong border security bill.

As for Obamacare, a symbolic abolition that Obama will immediately veto is less important than multiple rapid fire measures to kill it with a thousand cuts. Repeal of the medical device tax. Repeal of the individual mandate. Repeal of the employer mandate. Repeal of the coverage mandate, thereby reinstating Obama’s broken promise that “If you like your health care plan, you can keep it.” And repeal the federal bailout for insurers on the Obamacare exchanges.

If Obama issues vetoes, fine. Let the Democrats defend them for the next two years.

Then go big and go positive: Undertake a sweeping reform of the tax system, both corporate and individual, abolishing loopholes and lowering rates, like the historic Reagan-O’Neill 1986 reform or Obama’s own abandoned Simpson-Bowles commission. And go large: Invite the other side into immediate negotiations with the aim of producing a tax bill by spring.

How will Obama react? My guess – with the petulance and denial he displayed in his postelection news conference. Moreover, he will try to regain control of the national agenda with executive amnesty for illegal immigrants.

Final memo to the Republican Party: That would be naked impeachment bait. Don’t take it. Use the power of the purse to defund it. Pledge immediate repeal if Republicans take the White House in 2017. Denounce it as both unconstitutional and bad policy. But don’t let it overwhelm and overtake the Republican Party agenda. That’s exactly what Obama wants. It is his only way to regain the initiative.

Pass legislation. When Obama signs, you’ve shown seriousness and the ability to govern. When he vetoes, you’ve clarified the differences between party philosophies and prepared the ground for 2016.

Tuesday’s victory was big. But it did nothing more than level the playing field and give you a shot. Take it.

Charles Krauthammer is a columnist for The Washington Post. He can be contacted at:

letters@charleskrauthammer.com