Eric Liu: Does Marco Rubio Want To Create Second-Class Citizens? The Republican senator's plan for undocumented immigrants would create a two-tiered system of Americans Republican Sen. Marco Rubio speaks at the Pinellas County Republican Party's annual Lincoln Day Dinner in St. Petersburg, Florida on March 31, 2012 Liu's latest book is The Gardens of Democracy: A New American Story of Citizenship, the Economy, and the Role of Government. Many people lament that we're becoming two Americas - haves and have-nots, separate and unequal. But it's rare to see a public leader actually propose it. So I suppose you have to credit Senator Marco Rubio, Republican of Florida, for his candor. In recent days this son of Cuban immigrants has been floating an immigration proposal that would unabashedly create a two-tiered system of Americans: real and not real. Rubio's idea is a response to the DREAM Act, which once had bipartisan support but is now toxic to a GOP base that's become rabidly restrictionist. Under the DREAM Act, undocumented immigrants who serve in the military or go to college would earn a path to legalization and citizenship. Rubio's proposal, though, drops the "and citizenship" part. He concocts a new status that allows these immigrants to stay on American soil but bars them from becoming American citizens. MORE: Don't Pick on Immigrants: Re-Americanize Everyone Republicans often claim that the presence of undocumented immigrants undermines the integrity of our citizenship. But the irony is that Rubio would undermine it another way: by condemning millions of people to civic purgatory. What would it mean to create a huge cohort of un-citizens who can legally live among us, work for us and die for us but who cannot vote or serve on juries or get a passport? What would it be like to create a category of permanent guest workers branded by law as outsiders in perpetuity? It would be, in a word, un-American. Throughout this country's history there have of course been systematic efforts to create an official underclass. From slavery to Jim Crow, from Chinese coolies to Mexican braceros, minorities have been put in quasi-legal categories outside the bounds of citizenship, with fewer rights and substandard status. But the deep story of America is the story of such categories collapsing, one after another. In the end no segregationist scheme has withstood the force of a simple idea: equality under law. European nations like Germany don't hesitate to put migrants from Turkey in a long-term guest worker category with no outlet to citizenship. It's a way of getting a labor supply without having to alter the nation's identity. Japan, similarly, brings in guest workers from Southeast Asia or Latin America without ever making them citizens (or Japan any more pluralistic). But in the United States national identity is supposed to be defined by an idea, not by genotype. And the idea is that no one should be made officially second-class. That's why our own guest worker programs, so often abused, are so very troubling. It's also why we don't have permanent guest workers in the U.S. and why the real problem with Rubio's proposal isn't the way it addresses immigration; it's the way it degrades citizenship. MORE: Why Latino Voters Will Swing the 2012 Election While his idea is not as demagogic as the calls from other Republicans for vigilante seizures of the undocumented or mass deportation, it still would be a radical departure from the American way. The great majority of people in this country don't want a radical departure. They don't want second-class guest workers. They don't want a modern-day Fugitive Slave Act. They want better enforcement of the law and they want to give the undocumented who are here a reasonable and conditional path to citizenship. But citizenship itself has to mean more than the right to exclude. It has to mean a set of obligations to contribute affirmatively to the nation's strength. And it should apply, in the spirit of the Constitution, to every one of us. If the undocumented have to work hard to attain citizenship, those of us who already are citizens should have to work hard to sustain it. We should all have to serve more, vote more, build more, and do more for our country. In one sense, then, it really can be said that there are two kinds of Americans: those who earn it each day, and those who don't. The distinction has little to do with documentation status. You want to defend citizenship? Don't persecute or isolate those without papers. Just live like a citizen. That'd be a first-class way to be American. PHOTOS: An Immigration Detention Center in Arizona