The main talking points of Keystone advocates are that it's a big project, ready to go, and it will create jobs.
The main replies by Keystone opponents are that being a big project has nothing to do with being a good project; it may be ready, but we, as a country, are not ready for its consequences; it may create jobs, but they are not permanent jobs or green, sustainable jobs.
Keystone XL will produce more greenhouse gases because tar-sands gas consumes more energy than it delivers, tar-sands gas has byproducts so dirty that they must be shipped to China to burn, and much of the profit will go to Koch Industries, a company that has consistently tried to undermine our democratic institutions. We may not be able to stop the Koch brothers from spending vast sums of money to influence public opinion, but we should be able to stop allowing their egoistic schemes.
President Obama should look Keystone advocates in the eye and say, "You have opposed every single project I proposed to create jobs. You have given me nothing in return for this project. I can't stop the federal government from giving you tax breaks and subsidies, but I can sure stop you from building this pipeline."
Take a stand, President Obama. You speak for all of us.