The key difference between the immigrants of the 1840-1920 era and those of today is their legal status. The former group came to America legally, abided by the naturalization laws, and did not become dependent upon government sponsored welfare programs (as there were few such programs then, and none on the Federal level). Another difference is that the largest portion of the immigration has settled in the Southwestern states, adjacent to Mexico, which has long resented the loss of that region as a result of Texas independence and the Mexican War. Many of the immigrants, as evidenced by the recent demonstrations, and many residing in Mexico, as seen in opinion polls, believe that the U.S.-Mexican border should not exist. Thus, the Hispanic immigration into Texas, New Mexico, Arizona, and California more resembles the influx of Albanians into Kosovo than the standard immigration pattern.
It is also worthy to note that some of the strongest voices against illegal immigration are not exactly candidates for Ku Klux Klan or Nazi membership: Michelle Malkin (Filipino), Michael Savage (Russian Jewish), and Tom Tancredo (Italian).
And your technique of lumping me in with leftists is...
This thread isn't about illegal immigrants, it's about minorities in the US. And there are posters on this thread and elsewhere on FR who are explicitly anti-immigrant and anti-minority, regardless of their immigration status.