The Republican Party’s old guard that came of political age in the Reagan era and, not unlike their fellow baby boomers, who view failure to obtain what they want as the result of others’ shortcomings, are having a hard time of it.

Reince Priebus Reince Priebus in January 2011, after winning election as Republican National Committee chairman (Pablo Martinez Monsivais/Associated Press)

They assumed ever-increasing defense budgets. They took it as gospel that taxes are always wrong, everywhere and for any reason. They never dreamed anyone would question marriage is between one man and one woman, and they were certain that since Simpson-Mazolli they need only utter the word “amnesty” and pro-immigration-reform proponents would melt like the drenched Wicked Witch of the West. They have now adopted a “What’s the matter with everyone?” mix of annoyance and incredulity that their bedrock assumptions have crumbled.

They certainly are a grumpy lot. They rail at Republicans for not standing up to 70 percent of Americans who approve of women in combat. They find it maddening that most Americans, 50 years after the pill, now disconnect childbirth from marriage and marriage from economic necessity. And they even are peeved that the Republican National Committee itself has stepped up to the plate to suggest a raft of innovations and modifications in how the party operates. They are political Rip van Winkles minus the self awareness that it is they who have been sleeping for decades.

What do they believe in and what did they miss?

They believed winning white Americans (even independents) translates into winning competitive Senate races and the White House. So they ignored the huge demographic shift in the United States.

They believed “family values” means opposing abortion and gay rights. So they missed the tsunami that devastated heterosexual marriage, the rise in the number of single-women households and the shift in gay rights advocates’ tactics and the resulting revolution in public opinion.

They believed Republicans have a permanent advantage on national security and that the Cold War, which ended before everyone now under 40 years old had graduated college, proved once and for all Democrats were weak on defense. So they missed the legitimate war-weariness of the public, the perceived failures of the wars in Iraq and Afghanistan and the social distance between the all-voluntary military and average American voters.

Most of all, the old GOP guard assumed that particular problems Ronald Reagan faced would always be the issues conservatives should address and that the Reagan solutions were the essence of conservatism, not conservative solutions appropriate for that era.

They now confront an electorate as different from the Reagan electorate as the media that covered the Reagan presidency. Moreover, they face politicians and candidates both on the right and the left who came of age entirely after the Reagan era. These politicians have learned different lessons from Reagan and grew up in a different economic, political and cultural era.

The old guard may remain influential, but only if pols and pundits of that generation rethink their understanding of modern conservatism, find a new set of issues on which to focus and adopt new arguments to defend their party. And for the most part, the public face of the GOP must migrate from the ill-tempered, white, old men to a diverse, media-savvy generation that understands Americans of the 21st century. Then the essence of conservatism — the promotion of personal liberty — can survive and the GOP will endure as a viable national party. Right now, I think that is a 50-50 proposition.

This means coming to terms with the 21st century electorate, attending to the middle class pinched by stagnant wages and rising expenses, and developing a sober brand of internationalism to defend American interests. It means mastering new and old media and avoiding the trap of preaching to the choir. It means moving from the abstract to the specific and re-balancing power between an executive branch exceeding its proper authority and a Congress that has ceded traditional prerogatives. And it means finding fresher faces and more engaging voices to articulate the vision and agenda of the new right.

This is not so much a face-off between conservatives and moderates but between those who treat conservatism as a fragile museum piece to be guarded under glass and those who see it as a political disposition and an approach to governance and public policy. Is conservatism a political disposition or a set of fixed policy prescriptions etched in stone in 1980? The answer to that will determine the future, if any, of the GOP.