Of all the lessons to be gleaned from Ken Cuccinelli's narrow loss in the Virginia gubernatorial election, here's the one I fear Republicans will refuse to learn: The McCain and Romney campaign strategy of running away from debates over values issues is an abject loser.

Cuccinelli's opponent, Democratic moneyman Terry McAuliffe, saturated the Old Dominion with television, radio, print and online ads accusing the Republican of everything from wanting to confiscate women's birth control pills to endorsing laws to end divorce.

Cuccinelli barely responded, and when he finally did, it was too late. For most of the campaign, he steered clear of social issues.

Just one example: when Cuccinelli was asked during a candidate debate whether he would toughen Virginia's abortion laws, he said, “I do not expect to use the political capital of the governor's office to be moving those pieces of legislation. My focus is on job creation and job growth.”

Meanwhile, McAuliffe ran 5,600 ads on abortion alone, most pillorying Cuccinelli for his supposed extremism.

Cuccinelli's campaign followed that same model that Sen. John McCain, R-Ariz., and former Gov. Mitt Romney, R-Mass., employed against President Obama in the last two presidential campaigns -- and he suffered the exact same fate.

McCain and Romney discussed their beliefs on life, marriage and other social issues only when pressed, and then often awkwardly or apologetically.

Romney seemed especially reluctant to speak up, not only in debates but also in paid advertising. According to a recent report by American Principles in Action, out of more than 120 different television ads and $400 million in spending in 2012, the Romney campaign released just three social issues ads, and just one on abortion.

This virtual silence did two things: It allowed Obama’s positions and record on social issues to remain largely unexamined and unchallenged, and it allowed Obama and his allied groups to attack his Republican opponent with impunity.

McAuliffe, like Obama and most other Democrats, opposes abortion policies that enjoy overwhelming support among the American public, including bans on taxpayer funding of abortion, late-term abortions, waiting periods and parental involvement laws.

McAuliffe’s abortion views would have been a liability—had Cuccinelli raised them. A pre-election poll conducted by Public Opinion Strategies found that when Virginia voters were told that McAuliffe “supports using taxpayer dollars to pay for abortions,” 55 percent said it made them less likely to support him.

Virginia Democrats knew Cuccinelli’s retreat on social issues would hurt him. That’s why the Virginia Democratic Party delivered robocalls to Virginia voters blasting Cuccinelli for saying “he’s not focused on being pro-life anymore.” It seemed to work. According to exit polls, McAuliffe won 30 percent of self-identified pro-life voters.

Given the way some recent Republican candidates have botched sensitive questions about abortion and women’s health, it is understandable that even more articulate pro-life candidates would be hesitant to speak up.

But the easiest and most effective way for any pro-life candidate to expose their opponents’ extremism is simply to ask: “Is there any abortion my opponent would restrict? Name one.”

Or: “Would my opponent be troubled by an abortion designed specifically to end the life of an unborn baby girl or intended to end the lives of babies based on race? What about abortions during the 8th month of pregnancy?” These are all abortions most Democrats tacitly or explicitly support, including Obama and McAuliffe.

In the end, whether or not Republican candidates want to discuss abortion and other social issues is irrelevant.

That's because Democrats will continue to raise them, in 2014, 2016 and indefinitely until Republicans decide to fight back.

Former presidential candidate Gary Bauer is president of American Values and chairman of the Campaign for Working Families.