The Democratic candidates go head-to-head for the first time tonight in Las Vegas.  Nobody expects the kind of cage match we saw at the first GOP debate but that's not because the candidates necessarily agree.  We've come up with five key questions where the five may not see eye to eye:  1. If elected president, what are you prepared to do to reduce gun deaths?  In this Sept. 29 photo, Josh Tishhouse carries his Glock pistol at Gallup Park during an open carry pizza party in Ann Arbor, Michigan.  Image: Dominic Valente/The Ann Arbor News/Associated Press  In terms of reducing gun deaths, the research is clear: more guns means more gun deaths. But it's one of the most contentious and divisive issues — especially among the Democrats — with Bernie Sanders out of lockstep with his liberal base.  2. What's your strategy for fighting the Islamic State and other extremists groups in Syria and Iraq?  In this Oct. 22, 2014 photo, thick smoke from an airstrike by the US-led coalition rises in Kobani, Syria, as seen from a hilltop on the outskirts of Suruc, at the Turkey-Syria border.  Last week, the Obama administration finally abandoned its plan to arm and train moderate Syrian rebels. With Russia and Iran now involved, too, candidates will be expected to have a clear strategy for dealing with the conflict in Syria.  3. Do you believe it's more difficult for black Americans and other minorities to succeed in this country than it is for white Americans?  Baltimore Police Commissioner Kevin Davis, left, talks to activist Kwame Rose during a protest at the Baltimore courthouse on Sept. 10.  A question like this opens the door for candidates to discuss many issues in the news this past year, such as how police violence disproportionately affects black Americans; how voting rights for minority Americans have been rolled back and how sentencing for certain crimes disproportionately affects black Americans, among other things.  Perhaps more importantly, a question along these lines can reveal how much the candidates have thought about racial inequality in America.  4. What steps would you take to reduce economic inequality in America?  Traders work on the floor of the New York Stock Exchange, on Oct. 12.  Vermont Sen. Bernie Sanders has railed against economic inequality for much of his political career, and he has repeatedly said he's not taking money from Wall Street to run his presidential campaign. Former Secretary of State Hillary Clinton, however, has taken plenty of money from the financial sector.  The question would highlight one of the major differences between the frontrunner (Clinton) and her biggest challenger (Sanders).  5. How do you plan to reduce the number of inmates in U.S. prisons?  Corrections officers walk next to a fence covered in razor wire as they leave work at the Clinton Correctional Facility, on June 15, in Dannemora, New York.  Republicans and Democrats alike acknowledge overcrowding in American prisons which are also disproportionately filled with black and minority Americans.  Sanders has long advocated against harsh sentencing laws and has pushed for legislation, which would abolish for-profit prisons. Clinton, meanwhile, laid out her plans for prison reform in the spring. The debate on Tuesday offers an opportunity to compare on contrast on this issue, as well.  Have something to add to this story? Share it in the comments.
Democratic presidential candidates will debate each other on Tuesday in Las Vegas for the first time this campaign cycle.