Politics, like much in life, tends to move like a pendulum, shifting back and forth around equilibrium. While the liberal Democratic coalition is ascendant now, a few decades ago people were speaking about the decline of the Democrats. More recently, leftists took to calling themselves “progressives” to avoid what was seen as the pejorative term “liberal.” And just over two years ago, the Democrats took a drubbing in the midterm elections. Today, with the real-time flow of unfiltered information via blogs, YouTube, Facebook, FB +1.39% Twitter, etc., and more Americans self-identifying as independents and able to shift their support rapidly to either party, lasting coalitions will be difficult to maintain.

But the primary reason today’s liberal Democratic coalition will fade is because the very policies it pushes sow the seeds of its own destruction. The coalition can survive over time only by allocating slices of our nation’s economic pie in a way that favors and placates its constituent members. But people, being human, will continually want larger slices of our economic resources, so continued success in placating those members, while at the same time adding the necessary new members, requires a continuing and ever-growing economy. A flat or shrinking economy will never generate the resources needed to feed the coalition.

Yet the White House and congressional Democrats are working to stifle economic growth. From their views on taxes and redistribution, to their policies on energy and regulation, liberal Democrats are standing in the way of the strong economy their coalition needs.