The United States has a relatively simple political environment. It has only two strong parties, and they are in command. No other party can get anything through.
Our government was created with multiple checks and balances to stop stupid things from getting done. But sometimes this also stops smart things from getting done.
Every government in power tries to DO things. Yes, the GOP claimed it is for small government, but under every GOP president - including Reagan and both Bushes - it grew. The amount of money the spent went up, the number of laws that existed went up, in every way it happens.
The People in Power DO things.
The people out of power can't do things. If they could do something, then they would be in power. Instead, they do their best to limit and prevent things they disike from getting done. It isn't just for the American government, it works in any shared power relationship where one side has much more power than the other.
Things aren't getting done. That is beyond a doubt true. Which means the people without real power are being obstructionistic and stoping things from getting done.
So now the question is - who is in power: Democrats or Repbulicans.
If you think the Democrats are in power - then it is the Republicans fault nothing is getting done.
If you think the Republicans are in power, then it is the Democrats fault nothing is getting done.
Anyone that says "the democrats are refusing to cooperate with the Republicans" is in effect claiming that the Republicans are in control of this country. That they have the power and the Democrats are working behind the scenes to obstruct them.
The president is a Democrat. The Senate is majority Democrat. Yes, the GOP has a majority of the House, but that just makes them powerful enough to stop everything from getting done.
If one part has a huge amount of power i.e. control of all three of the following (control of the senate - which equals 60+ - and control of the House) then things get done fast.
If one party partial control of the senate and control of the house, then things get it's clear who is in control and who is being obstructionist (the minority party using filibustering). This is what happened during the first two years of Obama's presidency and the GOP was clearly and obviously obstructing government.
But if the House and Senate are split, then it gets a bit harder to tell who is being obstructionist. The Presidency has some additional power (as shown by Obama's orders about illegal immigration). But that could be countered by the claim that the Supreme Court is conservative biased. (Justice Scalia has revealed his deep and improper hatred for how the democrats do things - even while accepting the exact same things being done by GOP when they were in power.) While he isn't the only Judge, most of the judges currently in power were appointed by Republican presidencies.