The just-ending 113th Congress was not, by most measures, productive. But its endgame was at least instructive.
As a trillion-dollar omnibus spending bill trundled into law, the populist wings of both political parties declared themselves both revolted and in revolt.
The bill, complained Sen. Ted Cruz, R-Texas, "does nothing, absolutely nothing to stop President Obama's illegal and unconstitutional amnesty."
"Who does Congress work for?" asked Sen. Elizabeth Warren, D-Mass. "Does it work for the millionaires, the billionaires, the giant companies with their armies of lobbyists and lawyers?"
While this unexpected alliance of outrage did not prevail, it managed to preview some of the most important debates leading up to the 2016 election.
The challenge from the populist right is now familiar, but it is far from spent. Conservatives offended by the omnibus — and even more offended by Obama's immigration executive order — wanted to do something. This is often the whole substance of conservative strategy: "do something." After blowing up the Senate process and disrupting the travel plans of their colleagues, Cruz and company demanded a point-of-order vote on whether Obama's executive order was constitutional. Only 22 senators supported it.
With all the charm and appeal of nails scratching on a chalkboard, of screeching children on an airplane, of dogs yelping endlessly in the night, Senate conservatives forced a symbolic vote that ended up symbolizing their broad repudiation. But at least "something" was done.
The open revolt of the populist left is more novel. In this case, it was a rebellion against a sitting Democratic president, joined by former Democratic House Speaker Nancy Pelosi, forcing the White House to conduct a last-minute scramble for votes. The main provision at issue was the swaps "push-out" rule of the Dodd-Frank financial services reform bill. But Warren used the occasion to throw a large rock into the Democratic pond. The ripples radiate.