Scott Walker says he would consider building a wall along the U.S.-Canada border. "That is a legitimate issue for us to look at," the Wisconsin GOP governor  and presidential candidate told Chuck Todd in an interview that aired Sunday on NBC's "Meet the Press."

Legitimacy might be in the eye of the beholder. While the United States does deport illegal Canadian immigrants, the border with Canada is much longer, and the number of illegal immigrants crossing it is much, much, much smaller than it is down south.

We dug through statistics from the Department of Homeland Security's annual yearbook of immigration statistics to figure out how a fully functioning wall across the U.S.'s 4,000-mile northern border (excluding Alaska, which would add another 1,400 miles) would change our nation's immigrant flow.

The most recent data is from fiscal year 2013, or October 2012-September 2013. For comparison's sake, we've added deportation numbers from Mexico. (The nationality numbers don't include people from other nations who cross from Mexico or Canada, for example Salvadorans crossing the Mexican border.):

  • A U.S.-Canada wall would save immigration agents from having to arrest 822 Canadians (compared to 424,978 Mexicans) -- presuming all were arrested after crossing the border.
  • Border agents in Spokane, Wash., wouldn't have had to arrest 299 people (compared to the 11,154 people border agents in El Paso, Tex., arrested).
  • The U.S. possibly wouldn't have to deport all 793 Canadians that it did in 2013 (a wall wouldn't have stopped everyone -- some presumably came over legally before running afoul of immigration laws and being deported.) By comparison, 314,904 Mexicans were deported.
  • It might have stopped many of the 376 Canadians who had a criminal record when they were deported from coming into the country, assuming some of those Canadians crossed the border illegally. (For comparison, 146,298 Mexicans with a criminal record were deported.)

Needless to say, we're not going to be talking seriously about a northern border wall any time soon. This is more about ratcheting up the rhetoric on immigration reform -- which is at a premium now thanks to Donald Trump -- and these numbers prove that.