I’ve been watching debates since 1976 and don’t recall a worse thumping delivered to any candidate, let alone to an incumbent president. But to Mitt Romney and Rep. Paul Ryan (R-Wis.), conservatives should be delivering a simple message: Don’t get cocky.

The Romney-Ryan team needs to string one on-message day after another and use the debate performance as a rallying cry to conservatives and as an invitation to undecided voters.

As good as Romney’s performance was — and it was very good — there are lessons to be learned from the debate and gaps yet to be filled in Romney’s case against President Obama.

First, Romney needs to directly challenge Obama and debunk his $4 trillion debt-reduction plan. It’s phony. It’s symptomatic of the say-anything-do-little presidency.

Second, Romney was accused of vagueness in his plan, an echo of the liberal media’s mantra that Romney has no details. He should be able to turn the tables on the president on this point. Where is Obama’s long-term Medicare fix? Where is Obama’s comprehensive tax plan for individual taxpayers? Where is the comprehensive immigration plan Obama says he wanted to pass? Romney has a detailed Medicare premium support plan. He has laid out a comprehensive tax plan on both the corporate and individual side, and has now given some suggestions for how to meet his pledge of revenue neutrality without affecting the tax code’s progressivity. Romney laid out the key points in a comprehensive immigration plan. He can make some headway on this point.

Third, almost comically in the wake of the Libya debacle, Obama had the chutzpah to say the first task of a president is to keep America safe. (“The first role of the federal government is to keep the American people safe. That’s its most basic function.”) Romney should have leapt, and he can still pounce on that obvious clash between Obama’s words and his actions (slashing defense, leaving the Libyan consulate unprotected, failing to halt Iran’s nuclear weapons program). Obama’s obvious desire to disengage from the world in order to boost his electoral prospects (e.g. altering the Afghanistan troop withdrawal schedule) should be a point of attack for Romney.

Fourth, Obama revealed how puny his own job growth plan is. He wants to hire 100,000 teachers. (Do we need them? Why teachers and not health-care workers?). We have 23 million people without jobs. The sequestration, which Obama insists on using to extract a tax hike, will result in 200,000 layoffs, twice the number of teachers.

And finally, Romney should forcefully rebut the idea that we are on the right track. Growth is lower than it was in 2010. We are creating fewer jobs than we were even six months ago. The 2012 economy is the worst ever for a year that isn’t technically a recession. In large part because of the fiscal cliff, we may be looking at a recession in 2013. Obama’s “recovery” is the worst, ever.