Today, the Secret Service is authorized by law to protect:
The President, the Vice President (or other officer next in the order of succession to the Office of President, should the vice presidency be vacant), the President-elect, and the Vice President-elect
The immediate families of the above individuals
Former Presidents and their spouses for their lifetimes except when the spouse divorces or remarries. In 1997, legislation became effective limiting Secret Service protection to former Presidents and their spouses for a period of not more than 10 years from the date the former President leaves office making Bill and Hillary Clinton the last to receive lifetime protection
The widow or widower of a former President who dies in office or dies within a year of leaving office for a period of 1 year after the President's death (the Secretary of Homeland Security can extend the protection time)
Children of former Presidents until age 16 or 10 years after the presidency.
Former Vice Presidents, their spouses, and their children under age 16 for a period of not more than 6 months from the date the former Vice President leaves office (the Secretary of Homeland Security can extend the protection time)
Visiting heads of states or governments and their spouses traveling with them, other distinguished foreign visitors to the United States, and official representatives of the United States performing special missions abroad whom the president deems important enough for protection outside the Diplomatic Security Service
Major presidential and vice presidential candidates
The spouses of major presidential and vice presidential candidates (within 120 days of a general presidential election) Other individuals as designated per executive order of the President National Special Security Events, when designated as such by the Secretary of Homeland Security http://en.wikipedia.org/wiki/United_States_Secret_Service
Sop just by those 2 standards, Barry and company can shut down ALL protests as they see fit.