Tim Kaine isn’t giving up  on his demand for a new authorization for the war on ISIS:
Democratic vice-presidential candidate Tim Kaine said he didn’t believe the U.S. had legal authority to carry out airstrikes against Islamic State militants in Libya this week, underscoring differences over the issue with his running mate, Hillary Clinton.
Kaine has been one of the few members of Congress to challenge the administration line that the 2001 AUMF gives the president the authority to bomb ISIS targets. His criticism of the administration’s specious legal arguments has distinguished him from the vast majority of his colleagues, who either don’t take Congressional responsibilities seriously or share the overly broad view of executive power that Obama holds. Congress has been delinquent in its constitutional duties regarding this war for two years, and I doubt that will change anytime soon, but Kaine deserves credit for continuing to draw attention to Congress’ failure and the illegality of the war on ISIS.
Daniel DePetris comments  on the implications of allowing presidents to initiate wars on their own:change_me
The net result is that the president ignores the law, and Congress refuses to hold him accountable to it. The lethargy of inaction has effectively amended the Constitution so that Congressional approval is no longer required for war and peace decisions. It now resides exclusively in the hands of a single individual: the president.
The very thin silver lining of having Kaine on the Democratic ticket is that one of the top members of the next administration might be committed to challenging this drift towards unchecked presidential warmaking, but with Clinton as president it seems unlikely that these concerns would be taken seriously. While it is interesting that Kaine hasn’t stopped talking about this issue, he is still just the vice presidential nominee and won’t be the one making decisions in a Democratic administration. Clinton will be happy to abuse the 2001 AUMF just as Obama has to expand the war on ISIS to three countries (and counting), and she will do so knowing that one of the few critics of this practice won’t be in the Senate to complain about it any longer.
The debate over legal authorization obscures the fact that there still has never been a meaningful debate over the merits of the policy (or lack thereof). Virtually no one in Congress opposes the ever-expanding war on ISIS, and yet it is a prime example of an avoidable war of choice. There is little doubt that if Congress did vote on a new resolution that they would overwhelmingly approve a war that they have tacitly accepted for years, but it remains as unclear today as it was two years ago how the war makes the U.S. or its allies more secure.