How Will Bernie Sanders Influence the Democratic Party Platform?

One reason Bernie Sanders is pushing on until the Democratic Convention in July is his desire to shape the official Democratic party platform. Every four years, both parties hash out what they stand for in their official platforms. They are essentially party manifestos. Well, both sides began work on their platforms this week. Sanders hopes to push the Democratic platform further to the left. But do the platforms actually matter and do politicians adhere to them once they’re elected?