A tax on soft drinks that are sugary, like one that is proposed in Philadelphia and has been endorsed by Mrs. Clinton, divides the GOP.
This can be looked at as the achievement of less sugar consumption or very regressive tax that falls more on the poor than to the rich.
While not the largest issue overall, the two candidates have fought over the issue and it could hit the entire country.
In the coming years, this could be a big issue as more states and cities use taxes to increase revenues or to improve the health of the citizens.
This week, Clinton became the first candidate for the White House to endorse explicitly a tax for sugary drinks.
At an event on Wednesday, she said the proposal in the Philadelphia to use a tax on soda to fund a universal prekindergarten was a very good idea.
Clinton said she favored the tax plan, which helps to fund education. Mayor Jim Kenney in Philadelphia talks of the tax not as a way in which to drive down the amount of soda that is drank, but as one that helps fight poverty in his city.
However, there is another way in which to view taxes on soda and that is it is a measure that hits those who are poor harder.
Lower income families in Philadelphia like other Americans who are lower income tend to drink larger quantities of soda than their richer neighbors. Therefore, it means they might be stuck paying a share of this new tax that is disproportionate.
Sanders said that making sure all families have high quality childcare and preschool that is affordable is one vision that he strongly shares with many.
However, he said he did not support paying for the proposal via a regressive tax on soft drinks that would significantly raise taxes on the low- and middle income Americans.
The proposed tax in Philadelphia would charge 3 cents for each ounce of sugar drink that is sold by the distributor, which would make it the highest proposed soda tax in the nation.