In order to achieve a dictatorship in a country, you have to go one of two ways. Either you have to foment a violent revolution, using the power of the military to seize the government, or you have to be voted into the position and seize the power slowly. In the USA, it is all but impossible to achieve the takeover via violent overthrow, and the separation of powers makes it difficult to take over via slow seizure of power. However, the plans of the progressives have been working steadily since the Woodrow Wilson administration, and the task is almost complete.
The legislative branch, for example, has ceded vast parts of its authority voluntarily. According the to the Constitution, only the legislature can make laws. Although not the first example of such an agency, the creation of the Environmental Protection Agency in 1970 is a good example. The EPA was founded by an act of the legislature and charged to protect the environment. Since then, the EPA has been writing "regulations" which are, in fact, laws. You can be prosecuted and deprived of freedom or assets for disobeying the regulations of the EPA. Instead of going through all the trouble itself, Congress has delegated the passing of environmental laws to an agency not beholden to the will of the voting public. There are dozens of other agencies so empowered to regulate everything from food and medicine (FDA) to airplane travel (NTSB and FHA) -- all making laws without even a tacit nod to the citizens.
In fact, there are, according to a recent article in the Washington Post, 1.43 million civilians working for the federal government in various bureaucracies, and if state and local governments are taken into account, the number spikes to near 21 million by some estimates. Contrast this with the mere 535 elected members of the federal legislature. Many of these agencies require Senate approval for the presidential appointee to lead them. However, others require no such Senate approval, and presidents often get around the approval process via "recess appointments" such as the one used by Obama in 2010 to install a new chief of Medicare. Through the passage of the legislation known as ObamaCare, Congress has ceded all regulation of the health insurance and medical industries to the Department of Health and Human Services and the latter's presidential appointee. The financial services reform bill created the Financial Services Oversight Council and literally gave that council the power to regulate and monitor any financial transaction in America without a court order, as well as the ability to summarily seize businesses without judicial review or public disclosure. If passed, the cap and trade bill would give even more sweeping powers to the EPA.
However, the Federal Reserve is probably the single most dangerous entity in existence in America. The Federal Reserve has the power to create money electronically at will, set interest rates, and buy whatever it wants in the economy with practically no need to consult Congress for approval.
When it comes to violating the separation of powers and seizing executive power, no president has done more since FDR than Obama. What is more, Obama doesn't even try to hide the maneuvering, but instead does it out in the public eye. By his first state of the union speech, Obama had successfully passed TARP II and III, giving the secretary of treasury (executive branch) sole discretion over a sum of money equal to the budget of some small countries, and passed the stimulus bill, giving presidential allies big payouts. During the state of the union speech, the president brazenly said that he would establish his debt commission by executive order because the Senate refused to pass the bill that would have allowed it. It is worth noting that an Executive Order is issued solely by the president and is virtually impossible to overturn. In order to overturn an executive order, the Supreme Court would have to strike it down (which has happened only twice) or the Congress would have to muster enough votes to overcome a presidential veto of a bill passed in direct contrast to the executive order. Therefore, an executive order is not really that far from a dictatorial edict, and Obama has made frequent use of the technique. However, the Obama administration isn't picking on only the legislative branch. When the Supreme Court ruled that corporations should have the same freedom of speech in political campaigns as labor unions, Obama took the opportunity to publicly chastise the Supreme Court in his second state of the union address, while announcing his plans to circumvent the decision. The DISCLOSE Act, passed in 2010, went a long way toward that goal. Obama's political appointees have also been active in the field of law enforcement. In August 2010, the Houston Chronicle reported that Immigration and Customs Enforcement (ICE) ordered the dismissal of cases for deportation of illegal aliens who do not have felonies (other than the felony of illegal reentry) on their record. Furthermore, when two thugs with nightsticks from the New Black Panther Party were intimidating voters at a polling place, the Department of Justice charged the two defendants and received a summary judgment but were then ordered by political appointees to drop the case. According to whistle-blower DOJ Attorney J. Christian Adams, DOJ lawyers were ordered to not pursue any case for voter intimidation in which the defendant was black.
Never in the history of man has a government with highly centralized powers and minimal checks and balances ended well. Today, the executive branch in the USA has the power to do almost anything it wants. The legislature is all but powerless, having ceded all their authority to the executive-appointed bureaucracy. The judicial branch is still alive and kicking feebly, but the death or retirement of one conservative justice will put a stop to that. The law enforcement political appointees have become arbitrary in their enforcement of the law and politically motivated. Never has America faced such troubling times. All of this has been accomplished slowly and cautiously to avoid raising the alarm, because the powers involved definitely do not want to raise that alarm.
The only weapon left against the rise of the autocracy is the light of truth. If the vast majority of Americans, your neighbors and coworkers, knew all of this was going on, they wouldn't stand for it. Constitutional amendments would be passed, politicians would be dismissed, and corrupt politicians would be tried and jailed. We can only hope that the sword of truth can yet prevail. However, there is not much time left, and it is time we get to work in earnest.