Let me begin by asserting two propositions that are, in my judgment, incontrovertible.
1. If Clinton is elected president, under the best of circumstances the Democrats will take back control of the Senate but still fall far short of regaining the House. Therefore, Clinton will be utterly unable to shepherd incrementally progressive legislation to enactment.
2. If Sanders is elected president, under the best of circumstances the Democrats will take back control of the Senate but still fall far short of regaining the House. Therefore, Sanders will be utterly unable to shepherd radically progressive legislation to enactment.
What then would be the differences between a Clinton and a Sanders presidency? I suggest there would be two major differences, and possibly a third more important still.
A. Clinton would use the considerable executive authority of the presidency to deal lightly and favorably with Wall Street, in a manner that they would find comfortable. Sanders would use the considerable executive authority of the presidency to deal harshly with Wall Street, in a manner that would seriously interfere with their ability to milk the economy while risking another meltdown.
B. Clinton would embrace the Imperial project that has defined American foreign policy under all presidents since Truman. Sanders would adopt as non-imperialist a foreign policy as he could get away with without being impeached.
C. Clinton would do absolutely nothing to stimulate, encourage, or lead a movement designed to make radical changes in the orientation and distribution of power in the American political system. Sanders might undertake, as president, to lead such a movement.
These three differences lead me to conclude that Sanders would be a significantly better president than Clinton.
Now let me offer an opinion about which, I am well aware, there is considerable disagreement on the far left, where I hang my hat.
It matters greatly whether the Democrats or Republicans win the election for president. I do not want to argue for that opinion here. I have defended it elsewhere on this blog.
Thus, I [but perhaps not you] must ask: Which candidate, Clinton or Sanders, has the better chance to win? This strikes me as a much harder question to answer than the generality of political commentators suppose. In my judgment, Clinton would do better than Sanders against Rubio, and both of them would be able to defeat Cruz. But I also think Sanders would do better against Trump than Clinton. What leads me to these conclusions?
Against Rubio: Rubio would run a smooth, conventional center-right campaign, trimming back to the middle on immigration and expressing hawkish sentiments acceptable to the electorate. Clinton would run a center-left campaign, emphasizing experience and making as much as possible of the fact that she is a woman. Rubio would not do well with Hispanic-Americans, who are well aware of the unique and not much beloved position of Cuban-Americans in that community. Sanders and Warren would campaign vigorously for Clinton, and she would very probably win a strong but not overwhelming victory. Sanders, on the other hand, would be tarred and feathered as a commie [the hammer and sickle are already on exhibit], and would not have the unquestioning loyalty of the African-American voters.
Against Cruz: Cruz would run a hard-right campaign, and as Americans got to know him, they would come to loathe him as much as his Senate colleagues do. He would lose badly.
Against Trump [who still is, in my judgment, the probably nominee]: Clinton, I fear, would do badly against Trump. She is an awkward campaigner who does not inspire affection, and she would be vulnerable to Trump's non-stop outrageous personal attacks. I think he might destroy her. Sander s would be completely invulnerable to Trump's style of attack. Aside from his age, there is really nothing personal about him that could be a target for Trump. Sanders would leach away some of the working-class White support that has buoyed the Republicans for decades now, potentially winning a big victory.
What to do? Wait and see who gets the nomination, I guess.