According to a blog by "The Economist", Bernie Sanders endorsed Hillary Clinton for the presidency. She hails from and is supported by the Democratic establishment.
In other words, Sanders has been a liar and a fraud. During his entire presidential campaign, he criticized the elites in and the policies of the establishment. Yet, he now supports a champion of the Democratic establishment.
What should the supporters of Sanders do? In general, what should the voters do? They should carefully consider the remaining prominent candidates who are qualified to be president. They include Gary Johnson (of the Libertarian Party), Jill Stein (of the Green Party), and Donald Trump (of the Republican Party).
Hillary Clinton is not among those 3 people because she disqualified herself from the presidency when her callous indifference to the situation in Libya resulted in the death of ambassador Christopher Stevens. According to a blog by "The Economist", the officials at the Department of State wasted precious time in arguing with the officials at the Department of Defense before the impending deployment of soldiers to Benghazi to protect Stevens. The argument involved the type of uniform that the soldiers should wear. If Chelsea Clinton (the daughter of Hillary Clinton) instead of Stevens had been the ambassador to Libya, would Hillary Clinton have acted differently and would she have run the Department of State differently in order to ensure that Chelsea Clinton is safe from harm? Answering "yes" to this question means that Hillary Clinton should not be president.
Among the candidates who are qualified to be president, select the candidate whose policies (which he supported before becoming a presidential candidate) most closely align with your views. Stein and Trump have the same position on numerous policies. They support the single-payer system of national health care, oppose free-trade agreements like the Trans-Pacific Partnership, and support a significant increase in the minimum wage. Their political positions differ sharply from the positions of Johnson.
There is an additional factor that you must consider when you decide between Trump and Stein (or Johnson). The additional factor is personal character.
Whereas the litmus test for Sanders is whether he will endorse Clinton, the litmus test for Trump is whether he will select a woman for vice president (VP). Trump has been constantly making insensitive remarks which have created grave doubts about his character in the minds of the voters. For example, his mocking the imprisonment of Senator John McCain in Vietnam was extremely inappropriate.
To fix this political damage, Trump must pick a female VP. A tough, smart, and compassionate VP from the feminine gender will show that Trump is, in his heart of hearts, a decent person. In this case, picking a woman for VP is not about pandering to women but, rather, is about showing that Trump is not a bigoted misogynist.
Picking a VP is his first, significant test of good judgment. Picking a male VP means that he fails this test. If he fails this test, then voting for Jill Stein (or Gary Johnson) is a reasonable option.