If you replace the celebratory and joyous spirit of the song with disgust and despair, Dayenu is not a wholly inappropriate response to the vile nonsense spewing from the Republican candidates running for president. Their positions on any of a number of keys issues certainly would be enough -- standing alone -- to vote against them.
It would be enough to vote against the Republicans if only for their denial of the existence of man-made climate change and/or their unwillingness to do anything to combat global warming. GOP candidates running for president would hobble the EPA, negate Obama's executive actions to reduce carbon emissions, support the gutting of environmental regulations aimed at ensuring clean air and water, and expand the production of fossil fuels regardless of the environmental consequences.
It would be enough to vote against the Republicans if only for their extreme positions on women's reproductive rights, including their desire to overturn Roe v. Wade (and nominating Supreme Court justices committed to doing so) and defund Planned Parenthood. While essentially all of the GOP candidates are anti-choice, many go so far as to support banning abortion even in the case of rape and incest (e.g., Rubio, Carson, Huckabee, Paul, Jindal, Santorum) or support exceptions for the life (but not the health) of the mother (Jeb!, Cruz).
It would be enough to vote against the Republicans if only for their opposition to immigration reform, and their inhumane proposals that range from building a wall between the U.S. and Mexico, abolishing birthright citizenship for children born to undocumented immigrants, freezing green card applications, and mass deportation. These positions, as noted below, have only gotten more extreme in the wake of the Paris attacks.
It would be enough to vote against the Republicans if only for their opposition to raising the minimum wage while proposing tax plans that provide enormous gains for the top 1% and a pittance for the middle class. Republican candidates continue pushing failed economic theories that benefit the wealthy but cause widening inequality, less economic growth and higher unemployment. Indeed, the partisan disparity in job growth is stunning: under Obama, the U.S. added an average of 107,000 jobs a month; under Clinton, 240,000; and under Bush, 13,000 jobs a month.
It would be enough to vote against the Republicans if only for their potential nominations to the Supreme Court. Given the advanced ages of several of the justices, the next president will most likely have the opportunity to appoint more than one new justice, thereby impacting the balance of the Court for at least another generation. Another Republican appointee would create a rock solid conservative majority that would surely overturn Roe v. Wade, further dismantle Voting Rights, revisit and overturn the Affordable Care Act, dismantle federal regulations on everything from the environment to Wall Street, further limit available remedies for individuals against corporations, allow for greater intrusion of religion into the public sphere, and roll back advances in civil rights and criminal justice.
It would be enough to vote against Republicans if only for their desire to deregulate Wall Street. Dayenu! If only for their bigoted views on LGBT rights and what they euphemistically call "religious liberty." Dayenu! If only for their opposition to any reasonable gun control legislation. Dayenu!
And finally, and most recently, it would be enough to vote against the Republicans if only for their fear-mongering and senseless demagoguery in response to the terrorist attacks in Paris. Their ideas run the nonsensical gamut from insisting on using the term "radical Islam" (Rubio's linguistic solution) to closing mosques in the U.S. (Trump) to only admitting Christian refugees from Syria (Jeb!, Cruz) to closing our borders to Syrian refugees altogether (Carson, Rubio, Huckabee, Jindal, Paul) -- even to orphan toddlers (Christie). Trump would send back the refugees who are already here. They have nothing to offer but tough-sounding rhetoric. A prime example is Jeb!, who calls for us to "declare war and harness all of the power that the United States can bring to bear, both diplomatic and military of course, to be able to take out ISIS." He and his cohorts continue to rely on the same illogic -- and advisers -- used by Jeb!'s brother in responding to 9/11, conveniently forgetting that invading Iraq, dismantling the Baathist Party, relying on torture, and committing other inexcusable acts of incompetence created ISIS in the first place.