Gridlock is the situation where there is difficulty getting government to work because the  two legislative houses or the executive branch and the legislature are controlled by different political parties, or otherwise cannot agree.

The other day Bill Clinton attacked Sanders’s proposal for a single-payer health plan as unfeasible and a “recipe for gridlock.” But these days, nothing of any significance is politically feasible and every bold idea is a recipe for gridlock. This election is about changing the parameters of what’s feasible and ending the choke hold of big money on our political system. In other words, it’s about power – whether the very wealthy who now have it will keep it, or whether average Americans will get some as well.

See Robert Reich:The Most Pragmatic Way to Fix American Democracy

Update Feb 14,2016:
Government Gridlock has involved taxes, a shutdown, a sequester, and the debt ceiling. Now it’s looks like it’s also going to include a Supreme Court appointment. 🙁