There is no doubt that immigration is one of the primary hot-button issues for the 2016 presidential election -- in particular the influx of those entering illegally or staying beyond their legitimate visas.

But a new Pew Research study calls into question the legitimacy of the concerns. The net numbers of immigrants, both legal and illegal, have dropped.

Pew gives three reasons for the drop: a continued sluggish economy, better border protection, and more deportations.

While the number of illegal immigrants caught at the border has decreased, this is largely attributed to fewer attempts due to the sluggish recovery from the Great Recession.

This drop represents a possible end to one of the largest scaled immigration movements in U.S. history:

Mexican immigrants have been at the center of one of the largest mass migrations in modern history. Between 1965 and 2015 more than 16 million Mexican immigrants migrated to the United States – more than from any other country --

With shrinking Mexican immigration, this places China and India as the fastest growing sources for new immigrants to the United States.

The movement towards returning to Mexico has multiple reasons: returning to friends and family, lack of economic mobility in the U.S., and the perception of a growing economy in Mexico.

The views Mexicans have of life north of the border are changing too. While almost half (48%) of adults in Mexico believe life is better in the U.S., a growing share says it is neither better nor worse than life in Mexico.

One thing the study did not take into account was the growing anti-immigrant attitudes in the United States and their impact on the decision for returning to Mexico.

Americans have had a long history of anti-immigration attitudes, often marked with outright violence toward the new arrivals. Yet as the new arrivals amalgamate, they become more accepted.

This is the paradigm that seems to central to the modern immigration debate: should immigrants be allowed to come without amalgamation?

While this will probably not be resolved by the 2016 presidential debates, it will remain a hot-button issue with non-European cultures being the predominant source of immigration.

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