For most conservatives, either of the top two candidates, Mitt Romney or Texas Gov. Rick Perry, would be a vast improvement over President Obama. Certainly, some immigration exclusionists would bristle at Perry, but is there any doubt he would step up border enforcement? And while Romney’s state health-care plan is his biggest liability, he seems intent on removing the one-size fits-all (and taxes all) ObamaCare. Both advocate a robust foreign policy. And when it comes to economics, both, I suspect, strongly agree with Larry Kudlow, who rejects the notion that the United States is in an inevitable decline. He writes:

Big government financed by easy money is a lethal economic combination. It must be reversed. We should be reducing the regulatory and spending state while keeping money predictably stable (and even re-linked to gold). The supply-side nostrum that worked so well for 20 years, beginning with Ronald Reagan, was low tax rates, light regulation, limited government and a hard dollar. Gold collapsed between 1980 and 2000 as stocks, jobs and the economy roared. The last 10 years? We’ve gotten the policy mix completely backwards. The results show it.

This is a Reagan moment. We need a new leader who can get the economics right and reverse our decline. Literally, for the whole world, nothing is more important.

If Romney and Perry agree on a great deal, how does each convince voters that he is the right person to get elected and then to lead an era of difficult but necessary change?

Electability is always a guessing game. Hillary Clinton made the argument that only she could attract working-class voters and independents. But Obama managed to do both and win in 2008. Ronald Reagan’s critics said he was too conservative, but he won Americans over, largely by his debate performances. Right now the conventional wisdom is that Romney is more electable, since he is perceived as ideologically less extreme and does not have to overcome bias against a Southern or, worse, “another Texas governor.” But Perry has his own appeal to plain-spoken, non-urban voters. He’s down to earth and can make the populist pitch more convincingly than Romney can.

As for governance, each has his claim to being the superior chief executive. Romney will argue about Perry (as Ann Richards did regarding George H.W. Bush in 1988): “He was born on third base and thought he hit a triple.” In other words, he inherited a low-tax, low-regulation, business-friendly state and “succeeded” simply by maintaining the status quo. Perry will argue that he sure knows how to keep prosperity going and has the boldness to insist on dramatic changes to make the United States more like Texas.

It’s an interesting debate between two accomplished candidates. Romney is plainly a detail-oriented manager; Perry is an instinctive politician. Romney is coming out today with some 59 proposals for job creation; Perry says to look at his four terms as governor.

So how does one beat the other? Well, one of them can flub up in a debate or two, undermining his appeal. There might be a gotcha revelation from Perry’s tenure that would bring him down. Voters could decide RomneyCare is a disqualifier for Romney.

But, more likely, I think, is that one will put together a more convincing roadmap (apologies to Rep. Paul Ryan) — that is, a narrative that explains how he is going to take the country from where it is to where it needs to be. He’ll have to convince voters he has the skill and tenacity to do it. And he’ll have to convince GOP voters that he knows precisely where he is going. Patience is scarce with learn-on-the-job presidents. Voters will have to buy into a vision that is revolutionary in some respects but not scary.

Absent a major gaffe, we won’t have a definitive answer soon to which candidate is going to succeed. We will, however, get some hints this week, beginning with Romney’s jobs plan rollout, about who is better at convincing us he is the right one to take us to where we need to go.