Under the current FDA (Food and Drug Administration) rules and regulations, GMO's are not required to be labeled as such on common food items- tomatoes, papayas, rice etc.
Many Americans do not know of the possible harm and repercussions from GMO's. In the U.S. alone, GMO's are in as much as 80% of processed food. If we were aware of the presence of chemicals, perhaps people would realize the widespread impact that these foods have on the environment, i.e. "the companies that make GMOs now have the power to sue farmers whose fields are contaminated with GMOs, even when it is the result of inevitable drift from neighboring fields." -NON GMO Project
In addition, this bipartisan issue should be solved with support from the majority of the population as most parties agree on this issue.