The most successful Republican presidential candidate of the past half century — Ronald Reagan, who was elected and re-elected with landslide victories — bore little resemblance to the moderate candidates that Republican conventional wisdom depicts as the key to victory, even though most of these moderate candidates have in fact gone down to defeat.

One of the biggest differences between Reagan and these latter-day losers was that Reagan paid great attention to explaining his policies and values. He was called “the great communicator,” but much more than a gift for words was involved. The issues that defined Reagan’s vision were things he had thought about, written about and debated for years before he reached the White House.

Reagan was like a veteran quarterback who comes up to the line of scrimmage, takes a glance at how the other team is deployed against him, and knows automatically what he needs to do. There is not enough time to figure it out from scratch, while waiting for the ball to be snapped. You have to have figured out such things long before the game began, and now just need to execute.

Very few Republican candidates for any office today show any sign of such in-depth preparation on issues. Mitt Romney, for example, inadvertently showed his lack of preparation when he indicated that he was in favor of indexing the minimum wage rate, so that it would rise automatically with inflation.

That sounds fine. But the cold fact is that minimum wage laws create massive unemployment among black teenagers. Conversely, one of the lowest rates of unemployment among black teenagers occurred in the 1940s, when inflation virtually repealed the minimum wage law passed in 1938, since even unskilled labor was paid more in inflated dollars than the minimum wage law required.

Even during the recession year of 1949, black teenage unemployment was a fraction of what it would be in the most prosperous later years, after the minimum wage rate was raised repeatedly to keep pace with inflation. One of the few benefits of inflation is that it can in effect repeal minimum wage laws, which politicians can do directly only by risking their re-election.

Conservative opposition to minimum wage laws is just one of the ways that conservative principles often work out to benefit those with lower incomes, more so than liberal principles that sound so much better as political rhetoric.

It seems unlikely that Gov. Romney had time to learn about such things during this year’s busy election campaign. He was like a rookie quarterback with just a few seconds to try to figure out the opposing team’s complex formations before the ball is snapped. One of the secrets of Barack Obama’s success is his ability to say things that will sound both plausible and inspiring to uninformed people, even when they sound ridiculous to people who know the facts. Apparently he believes the former outnumber the latter, and the election results suggest that he may be right.

Since most of the media will never expose Obama’s fallacies and falsehoods, it is all the more important for Republicans to do so themselves. Nor is it necessary for every Republican candidate for every office to become an expert on every controversial issue.

Just as particular issues are farmed out to different committees in Congress, so Republicans can set up committees of outside experts to inform them on particular issues.

For example, a committee on income and poverty could be headed by an expert like Robert Rector of the Heritage Foundation. This is a subject on which demonstrable falsehoods have become the norm, and one on which devastating refutations in plain English are readily available from a number of sources.

A committee on the counterproductive effects of liberal policies such as minimum wage laws on minorities could be headed by someone like economist Walter Williams. Here too, there are many writings in plain English that could expose the huge harm done to minorities by liberal policies that claim to be helping them.

It is not necessary to explode every single lie put out by liberal Democrats. All that is necessary is to thoroughly discredit a few of their key claims, exposing them as liars.

What is even more necessary is for Republicans themselves to understand the urgent need to do so, for their own sake and — more important — for the country’s sake.

Thomas Sowell is a senior fellow at the Hoover Institution at Stanford University His website is www.tsowell.com.