It all started in 1961 when the country was in the middle of a post-war rebuilding boom that was too much for its native labor force to handle. In response, Germany signed a treaty with Turkey that allowed it to import hundreds of thousands of temporary guest workers willing to do the dirty jobs. Germany's economy benefitted, but many of the immigrant workers ended up planting roots. And without a clear mechanism to integrate them, many were stuck as permanent residents for generations -- even German-born children, who were not automatically granted citizenship.
Fifty years later, the Turkish community in Germany numbers around 3 million and lags behind ethnic Germans in education, employment, and other quality of life categories. Having determined they had a problem on their hands, Germany reformed its laws in 1999 to ease the path to citizenship for immigrants and their children and the government has made integration a policy priority. But tensions still remain -- many Germans with foreign roots complain of discrimination and feeling alienated in their own country. A book by a German central bank official Thilo Sarrazin, "Germany Abolishes Itself," became a sensation calling for greater restrictions on immigration and decrying Turkish and other Muslim immigrants as incapable of assimilation.
To immigration reformers, the message is that the United States can't afford to leave its large undocumented population as second class citizens without breeding resentment on all sides and trapping communities in poverty.
"It hangs over the current debate because it keeps being brought in as an example of the mistakes we don't want to repeat in the United States," Marshall Fitz, director of immigration policy at the liberal Center for American Progress, told TPM. "Not only did Germany have their problems, but they recognized and reversed them to become more like us. The irony would be replicating their errors, which is why this keeps coming up."
As Fitz noted, Germany reformed its laws to be more like America's, which are unique among Western nations in that they grant unconditional citizenship to anyone born in the country. Because of this distinction, some experts say comparisons are weak at best between the two countries as the United States -- whatever its faults -- already has an automatic mechanism for assimilating large groups of immigrants if given enough time.
Mark Krikorian, director of the restrictionist Center for Immigration Studies, told TPM that America's birthright citizenship laws rendered most parallels to Germany moot in his eyes as a result.
"If we changed those citizenship rules you could have 250,000 U.S.-born illegal alien children a year and that would be a real problem -- maybe comparable to Germany's situation," he said. "But that's not really on the radar."
Experts take issue with other elements of the comparison, some for economic reasons, some social. Madeleine Sumption, a senior policy analyst at the Migration Policy Institute, suggested that Germany's and other European nations' difficulties have more to do with their labor laws than their immigration policies. America has much laxer regulations on hiring and firing workers, resulting in less security but also more opportunities for immigrants to find work compared to immigrant populations in other countries. U.S. law also bars illegal immigrants from most social services, which reduces another source of resentment that looms large in Europe, where -- for better or worse -- the mostly legal immigrant community enjoys a more generous safety net.
"Even if there is criticism of this type of labor market, it makes it easier to get a foot on the ladder," Sumption said. "The gap between unemployment rates of immigrants and native workers is much smaller in the U.S. than it is in most European countries."
Victor Davis Hanson, a senior fellow at the Hoover Institution and popular conservative commentator, cited cultural factors as the biggest dividing line. In addition to a less prolific history of absorbing large immigrant populations than America, he cited tensions with large Muslim immigrant communities in various European countries over issues concerning the role of religion in public life.
"All of the above make immigration a more explosive issue in the EU," he said in an e-mail. "That said, the general trends -- the poor and undereducated seek access into the general entitlement-rich West, where the economy is more robust and freedom more assured -- are also similar."
Still others drew lessons from Germany that could cut against elements of immigration reform. Jagdish Bhagwati, a professor of economics and law at Columbia University working on a book on immigration reform, told TPM that research suggested that the most relevant takeaway from Europe isn't the importance of citizenship, it's that "temporary" guest workers are unlikely to leave while the political costs of forcibly removing them in an open society remain high.
"The same is likely to happen here because we are even more into human rights," he said in an e-mail. "Enforcement of expulsion, just because it is written into the contract, is improbable."
U.S. policymakers are currently debating some form of temporary visa program for future workers which could include a legal route to permanent residency for longtime immigrants.
While the pro-immigration crowd is most likely to bring up Europe, they're not entirely alone. Civil unrest in places like Britain and France has occasionally been used by commentators opposed to reform to argue against large scale immigration in the United States and about the dangers of poverty among second-generation immigrants. But such comparisons are more rare lately.
According to Sumption, there's still plenty to be gained from comparing immigration policies country by country -- just take it with a grain of salt.
"I think there are some good relevant lessons that need to be taken in context," she said. "The problem is that examples are often used in an extremely simplified way in order to justify a preconceived view that the speaker wants to promote."