Marijuana legalization advocates and members of community groups attend a rally against marijuana arrests in front of One Police Plaza on June 13, 2012 in New York City. - 

Union workers in Michigan continue to voice their anger over a new right-to-work law signed by Governor Rick Snyder this week.

So how do Americans perceive unions? 

According to Gallup editor-in-chief Frank Newport, back in the 1930s when Americans were first asked about unions, 72 percent said they approved.

"This was in the middle of the Depression mind you," Newport adds.

Since then, that number has come down. Newport says current polls show 52 percent of those surveyed approve of unions. 

When it comes to the issue of legalizing marijuana, Americans are evenly split. Newport says 50 percent believe it should not be legal, while 48 percent of Americans hold the opposite point of view. 

In Washington State and Colorado, recent ballot questions on the issue of marijuana have pitted state law against federal law . But Newport says only 34 percent of Americans feel the federal government should interfere with state marijuana laws.