I may not be a supporter of his, but he meets all the requirements that we have laid out for him to run. I find it ridiculous to only have one person from each party running until the end. I myself like different options in the parties. If he doesn't get the votes against Hilary Clinton in the democratic party, then I hope he will stay on the trail, as it is his right to do so.
Hillary Clinton already has the number of delegates she needs to secure the nomination for the Democrats. Bernie Sanders knows this, but continues to press on. His perseverance is to be admired, but at this point it is turning into stubbornness that is only going to divide the Democratic party and cost them the election. He needs to end his campaign now, get behind Hillary, and work towards getting his supporters to do the same.
At this point, it's not wise for Sanders to stay in the race. He's stayed in long enough to influence the discussion and raise awareness of many issues he feels strongly about. But staying in much longer would potentially damage the causes he believes in by weakening Clinton's campaign against Trump attacks.
Sanders is finished and has no chance to win the democratic nomination. It is time for him to stop wasting everyone's time and he needs to leave the race immediately. There is no good purpose served at all to continue on a fruitless venture. Circle the wagons and help the party, but by all means get out.