(PHILADELPHIA) — The Democratic National Convention gets underway in Philadelphia on Monday with much bigger demonstrations than the Republican convention and much higher temperatures, as the region copes with an oppressive heat wave. In one of the largest rallies planned for the day, a pro-Bernie Sanders group is expected to walk across the Ben Franklin Bridge, which connects Camden, New Jersey, and Philadelphia. The demonstrations, largely driven by Sanders supporters, have been peaceful, so far. On Sunday, throngs of people marched along a main thoroughfare of the city to show their support for Sanders and their disdain for Hillary Clinton. They chanted “Hell No, DNC, we won’t vote for Hillary” and “This is what democracy looks like.” Though planned for months, the marches came as fractures appeared in the party that had been trying to display a show of unity in recent weeks.