Two weeks ago, Senator Marco Rubio (R-FL) gave an impassioned speech about Cuba and Venezuela on the Senate floor. This was his response to a floor speech by Senator Tom Harkin (D-IA), who had recently visited Castro’s Cuba and predictably came back with rave reviews of the Potemkin village.

Rubio dismantled Harkin’s rosy assessment of the hemisphere’s longest-running and bloodiest dictatorship. Many observers described it as Rubio’s finest demonstration of his oratory skills, and a speech that might put him back in the good graces of the conservative Republican base.

Marco Rubio has touched the third rail of conservative politics — immigration reform. He was the most visible of a group of Republicans that attempted to forge a compromise to help solve the problem of the estimated 12 million illegal aliens living within our borders. The issue is so toxic within the Republican Party that many simply wrote Rubio off despite the fact that the initiative didn’t go anywhere.

I never thought I’d see the day when a Republican would have to rehabilitate his conservative image after committing the sin of agreeing with the likes of Jack Kemp, Bill Kristol, Lawrence Kudlow, and Steve Forbes, not to mention Ronald Reagan. But that day has indeed arrived, much to my befuddlement.

The first time I saw Marco Rubio speak, it was in 2007 at a town hall meeting in Miami’s Coconut Grove neighborhood. At the time, he was Florida’s House speaker. His topic was reforming Florida’s backward property tax laws; Rubio was for scrapping the property tax on residences altogether. I remember thinking that Rubio had the right idea — and a gift for communicating why it was the right idea. I began blogging about and supporting Rubio. He did get House passage of his property tax proposal, however it was a no-go in the Senate. But he was making the right kind of waves.

In May 2008, Rubio upstaged the eventual Democratic nominee for president, Senator Barack Obama, at a Cuban American National Foundation luncheon with a rousing speech. He proclaimed: “There’s no statute of limitation on freedom.”

Even as speaker of the state House of Representatives, Rubio’s profile was relatively low. When he decided to throw his hat into the ring for Florida’s vacant Senate seat in 2010 — challenging the then-popular Republican Governor Charlie Crist — many observers thought his campaign was dead on arrival. But Rubio ran a brilliant insurgent campaign, and by the time all was said and done Crist had self-immolated and was without a job. Rubio had ridden the Tea Party wave into the U.S. Senate, and chased Crist from the Party in the process. When Floridians next cast their gaze on Charlie Crist, he was chasing ambulances.

I was fortunate enough to be Senator Rubio’s guest in the Senate gallery for his maiden speech. On that occasion, Rubio outlined his vision for a second American century, a vision that presented a stark contrast to Obama’s vision. Rubio’s star was still rising.

In 2012, Rubio was given a prime speaking spot at the Republican convention. In February 2013, Rubio gave the Republican response to President Obama’s State of the Union speech (and took the gulp heard round the world). As ridiculous as “the Poland Spring Affair” was, it coincided with the beginning of Rubio’s slide into disfavor. His substantive trouble came as he took it upon himself to outline what he labeled “conservative” principles for immigration reform. Initially there was some enthusiasm for his ideas, but as the year wore on and a bill came closer to reality, vocal conservatives intensified their rhetoric, labeling Rubio a traitor for having betrayed conservatism itself.

I was puzzled and a little angry about the reaction among some conservatives, with whom I see eye-to-eye on virtually everything.

I had been advocating for immigration reform for years, trying to allay fears and dispel myths about the largely Hispanic illegal aliens living in America. It’s not that I have a soft spot for these law-breakers (as we’re always reminded, never mind that entering the country illegally is classified as an administrative violation), it’s that I see immigration as an economic issue, and my supply-side economics background gives me a more libertarian view of it. Reason makes the libertarian argument for immigration reform brilliantly.

It doesn’t take a genius to understand that Republicans of both the conservative and libertarian variety need to coexist in order for the party to have a viable future. In fact, on many issues the libertarian wing is taking the lead. Insofar as the Tea Party is about smaller government, lower taxes, less debt, and more personal freedom, it’s operating in deeply libertarian territory. But somehow Rubio’s intent is a sin so unforgivable that many had written him off as just another RINO in the mold of John McCain and Lindsey Graham.

It should be noted that in 2013, the same year he took up the issue of immigration reform, raising the hackles of some conservatives, Marco Rubio scored a 96 on the American Conservative Union’s ratings, following up on a perfect 100 in 2012 and 2011. National Journal has Rubio rated as the 17th most conservative Republican in the Senate. Notably, the libertarian-leaning Kentucky Senator Rand Paul, who many see as a 2016 contender, is 19th.

Senator Paul espouses some views that I’d argue are just as qualitatively at odds with conservatism, if not more so, than Rubio’s views on immigration. For example, in the arena of foreign policy Paul is decidedly a non-interventionist. Still, I like Rand Paul and would vote for him in a New York minute if he were to be the Republican nominee in 2016.

I wonder when immigration reform became the litmus test on conservatism. Who made it that way? I wonder how a guy whom conservatives agree with on almost every single issue can be discarded at the drop of a hat because he differs with them on one — one which is way down the list of most voters’ priorities.

You’ve got to believe that eventually the millions of illegal aliens in the U.S. will be given legal status. And it would be foolhardy for the Republican Party to appear to be a group of nativists. One of the greatest rebuttals to liberalism is that it was largely the Democrats who opposed civil rights legislation in the 1960s. If not for Republicans, who were in the minority at the time, those laws would have never passed. Today blacks are overwhelmingly Democrats, but that doesn’t invalidate the rightness of the civil rights legislation itself. We need to have a real debate about how best to spread conservatism among minorities, but that’s a separate issue.

As the GOP prepares to possibly regain control of the Senate and to extend its majority in the House, the party has a golden opportunity to dictate the terms under which these illegals pass from the darkness of the underground economy into the light of legal status for the benefit of all Americans. But even if immigration reform isn’t passed in the near future, we should stop using this as a wedge issue on ourselves.