Al Cardenas may be the most important conservative you never heard of.

As an 11-year-old he and his parents fled Fidel Castro. At Seton Hall Law School in 1972, he filled in for the no-show Richard Nixon surrogate and took on George McGovern’s representative. And after decades in the trenches of the conservative movement, he now heads the American Conservative Union, the organization that William F. Buckley Jr. founded before other conservative issue advocacy groups or a single conservative think tank existed.

ACU is best known as the sponsor of the annual CPAC conference, one of the largest annual gatherings of conservatives. Now its role is as an umbrella organization, the board of which is stocked with leaders of prominent conservative groups.

ACU’s role in the presidential election, he tells me in his law firm’s brand-new D.C office, is to rally and turn out the base, especially in key swing states. “The swing states are rich in diversity, of thought and of ethnicity,” he tells me. He concedes that no candidate “suffered” more than Romney from the conservative base’s skepticism. In part, he thinks this was created by opponents who all claimed to be to Romney’s right. “It is our job to clear their minds of all that negativity,” he says of his role in energizing conservatives.

Cardenas contends Romney’s agenda is quite conservative and that polling shows the base has, in fact, rallied to him now. But why was there all that skepticism during the primaries? For one thing, Cardenas says, there were “the optics that he comes from Massachusetts.” He insists Romney governed as a conservative, but “instead of getting brownie points for carrying the flag in enemy territory, [conservatives] deduct points.”

Even evangelicals, who the liberal media said would never embrace him because of Mormonism, have taken up the Romney banner. He says they can see “he walks the walk” on his values and family life.

In Cardenas’s career, the GOP has seen the rise of a much more strident brand of conservatism, which some characterize as imposing “purity” tests on candidates. He says, “The good news is that it is a problem that both liberals and conservatives have.” He contends this is fueled by dozens of think tanks and other groups that are trying to prove their conservative bona fides and a media that loves to portray conservatives attacking conservatives. He also believes that conservatives look back on the George W. Bush era as a time of fiscal irresponsibility in which conservatives dropped the ball. “They’ve taken a blood oath not to let it happen again.”

However, he tells me that as a conservative he is pleased that there are groups “intent on keeping the needle right of center.” The challenge, however, is not to make it impossible for Romney to appeal to critical swing voters. Toward that end, Cardenas was heartened by Romney’s speech last night. Romney’s response to the Obama campaign’s divisive campaign, he says, is that “you don’t unite the country by dividing it.” He contends that “our policies are where they need to be” in the general election but that Romney will need to show concern for the hardships of ordinary people. “You don’t want an insensitive guy to be president.”

There has been much discussion about Hispanic voters, both in Florida and around the country. Cardenas concedes that the Hispanic community in Florida has changed dramatically from the days when it was dominated solely by Cubans. Today, Puerto Ricans are the second-largest Hispanic group in the state. Cardenas says Republicans enjoy solid support among those Puerto Ricans who come directly from the island (as opposed to from the deep-blue state of New York). And while Democrats keep saying the Cuban population is shifting left, Cardenas laughs, “They’ve been saying that for 25 years. Nothing has changed. I see no electoral evidence.” He then reels off a list of prominent Cuban politicians in Florida — all Republican.

As for the country at large, Cardenas notes that the polls may be misleading. While Republicans do very poorly with Hispanics in states such as New York and California, these are by no means swing states. (My own view: If Romney spends a dime in California or Illinois, he’s a fool.) What remains critical are the competitive states (and the Hispanic vote within those) — Colorado, Florida, New Mexico, Virginia, Nevada and Arizona. Cardenas says the GOP wants to win a majority of Hispanics in those states. He’s staying on message with that observation, but in reality if the GOP could simply raise its percentage among Hispanic voters in those swing states, it would be a huge help in getting to 270 electoral votes.

To accomplish that, Cardenas echoes the Romney message that the key to winning Hispanics, like all voters, is the economy. Cardenas agrees with the “Obama is in over his head” theme. He puts Romney’s argument this way: “This president just doesn’t have the bandwidth to deal with these complex problems and I do.”

Cardenas recalls that in 1980 Ronald Reagan was trailing by double digits until the convention and a debate or two. Jimmy Carter had painted him as “dumb, old and lazy,” and it took time for Reagan to disprove that image. Likewise in this election, with the Obama camp painting Romney as either a flip-flopper or an extreme right-winger (not exactly consistent is it?), the swing voters may decide in the final few weeks of the race. If Cardenas is right, look for a nip-and-tuck race to the finish.

While Romney recites his center-right agenda and goes fishing for independent voters, Cardenas and like-minded conservatives desperate to dump Obama will be out trying to drum up every conservative vote they can. We may not know whether that tag team is successful until the final days of the race.