I've been wanting to write this for a long time, but haven't. Current events are pushing me to point out the reality of the US political system.
Despite the founders intent of three separate branches and checks and balances: The real power is in the legislature
De facto describes practices that exist in reality, even though they are not officially recognized by laws. De jure is according to the law.
Law does not always reflect the reality.
The reasons I say that the US is a de facto parliamentary system should be obvious, but most people are distracted by the president that they miss the body with any real power is the legislature. The legislature holds the power of the purse, among many others that make it the strongest and most powerful branch..
The failure to pass a budget in any true parliamentary democracy would lead to automatic dissolution of the government. This is due to the concept of "loss of supply":
A defeat on a budgetary vote is one way by which supply can be denied. Loss of supply is typically interpreted as indicating a loss of confidence in the government. Not all "money bills" are necessarily supply bills. For instance, in Australia, supply bills are defined as "bills which are required by the Government to carry on its day-to-day business".
When a loss of supply occurs, a prime minister is generally required either by constitutional convention or by explicit constitutional instruction to either resign immediately or seek a parliamentary dissolution.
Some constitutions, however, do not allow the option of parliamentary dissolution but rather require the government to be dissolved or to resign.
The US system has specified terms limits, which is one way that dissolution of government resulting in new elections can be prevented. On the other hand, the US government could conceivably go into a prolonged budget crisis and government shutdown. That's one reason that US Budget crises tend to be short.
On the other hand, if one party really didn't like the other one. The budget crisis could last until the end of the legislative session.
Next reason why the US is actually parliamentary is that the legislature can remove the executive. While the criterion for doing this is "high crimes and misdemeanours": the reality is that it can be for frivolous reasons if one political party dislikes the executive of the other party. While the criterion is "high crimes and misdemeanours", the reality is that the process is blatantly political. That is because other executives have engages in "high crimes and misdemeanours" by violation of international law (e.g., illegal war) with little or no consequences.
On the other hand, don't lie about blowjobs.
Not sure where this comes into the strength of the argument, but the legislature offers the best place for representing the people. The legislature is directly elected and proportional to the population (at least in the house of representatives). On the other hand, it is one place where alternative parties can have a voice.
The president is not a directly elected, which is another place the legislature has control over that office. In a way, the current situation is like the English Civil War where the question was which body had the power: the monarch or the legislature?
The legislature (parliament) won the battle.
Those of us who feel the current system is not representative should put our efforts into getting alternative parties into congress: not being hopeful that either party will change. Tip O'Neill said "all politics are local".
Realising that the real power in the US is in the legislature is the beginning of the battle to bring about a change in US politics.