Other than a dual-presidency, nearly every office of Roman government was re-created within the American republic, except for one: the office of Tribune.
Obviously, the word is commonly associated with newspapers today, and the founders believed that the function of the office as it worked within Roman government, would be fulfilled through a free press.
The Romans realized after about 150 years of Republican government, that in any society where citizens were allowed to pursue public and private interests, possess property and form contracts with each other, eventually, a group or class of people would emerge with more power and resources than a majority of citizens, and that they would naturally have an interest in war, class conflict, and schemes to coordinate property and financial transfers.
The founders of the United States also discussed this in detail when drafting the Constitution and the Bill of Rights, and often spoke of a "natural elite" emerging within any democracy that must not be completely stifled by an envious majority in order to realize their potential, which usually benefited all in the long run.
Simultaneously, the emergence of a "natural elite," if unchecked by the law, was also seen as a threat to the majority as well, in that the "elite" would undoubtedly be able to coerce or buy the consent of the majority by force, deceit, the concentration and movement of capital, or by wielding all the powers of the government unchecked, inconsiderate of popular opinion and public welfare.
While the fashionable view among the intellectual "Left" today is to interpret all the commentary of the American revolutionaries and founders as racist, sexist, elitism, by rejecting all of their ideas in this way, the extremely insightful discussions into human nature stated above are virtually ignored, and the irrational, discriminatory superstitions that many hope to challenge by guarding against bigotry are simply reapplied.
While it's ridiculous to believe that some people are more capable, knowledgeable, or competent than others, solely on arbitrary grounds, such as race, gender, class, etc... It is not at all unreasonable to admit the varying capacities, talents, and capabilities that exist and are manifested by certain individuals. This is typically referred to as the "Iron Law of Oligarchy."
The founders understood that any society which faced up to this not-so-romantic characteristic of human nature, would need to provide freedom from popular tyranny, as well as from concentrated, centralized power in the hands of a small minority.
This observation of human capacity was, in fact, the starting point for the Constitution.
The simple fact is, even if we all started with the same amount of land and the same amount of resources, in any society where people can own and produce their own things and make agreements with each other; luck, combined with individual human capacity and the ability to act creatively, would inevitably lead to a small group of people who command more private resources, are more intelligent or skilled than others and thus able to act more effectively in the political arena.
The office of tribune evolved because an enriched and privileged minority enjoyed a substantial amount of power and control over the lives of the average citizen living in the Roman Republic, and an office was eventually created that allowed the popular majority to completely halt any proposed bill, any policy, or even any trial, if the Tribune brought the issue to their attention.
It was rarely used, but when it was, it was absolutely decisive and could not be overturned, except by another popular vote proposed by another tribune.
The office was officially created after the majority in Rome, the workers, traders, shop-owners, actors, soldiers, guards, and minor administrative officials, completely shut down the city by locking themselves in their homes or taking refuge in the surrounding area until the military/economic/political elites accepted their demands.
They did this for a number of reasons.
They were not allowed fair trials in the law courts, the wealthier citizens exploited, extorted and terrorized them, and they were excluded from ever being able to hold certain offices of government.
Even if they were able to amass enough wealth to provide their children with an excellent education, so that their abilities would place them intellectually alongside the entrenched elite, they would never be able to serve the public or earn public honors by virtue of their social status as "new" men. Basically, the system was completely set up against them and their descendants, forever, or at least status was seen as taking a few generations to gain.
Anyway, within a few days of the evacuation and protest, the "elite" begged the plebs to come back, newly equipped with the popular veto and the ability to access the law courts, and in this way, for nearly 200 years the city provided all of its citizens (obviously, slaves are the exception with the ability to live justly and to their fullest potential according to their abilities.
The plebs were integrated into the governing class and were slowly granted the ability to hold office and receive a fair trial, but most importantly to the history of democracy,the popular veto was created.
The responsibility of the Tribune was to prepare all the information relevant to the workings of government and the interests of elite private citizens as it related to the functioning of government, and to present it to the people in a way they could comprehend, so that a simple yes/no vote could be taken before a law was passed.
It was not a form of legislating or enacting policy, but rather a way to reject it when it obviously conflicted with the interests or values of a majority of the citizenry, or when it was judged that a decision regarding public policy was obviously being manipulated by a powerful citizen whose interest in the issue was petty, selfish, or exploitative.
The office was abolished only after the elite were allowed to hold it, and it was mis-used by the elite in order to enact policy that forcefully restrained the workings of the senate instead of rejecting authoritarian or corrupt proposals.
Afterwards, the office degenerated to the point where the authoritarian emperors claimed the "powers of the tribune."
The equivalent would be the president personally approving every article in every newspaper and every program on TV, as well as being President of the ACLU. Or possibly if a few wealthy interests possessed a majority of the media in this country and thus, controlled the ability of the majority to inform itself and comprehend the issues at hand, and the private interests of some citizens in regards to public issues. But, of course, we're a long way from this situation, aren't we?
The corruption of the tribunatary power was the first indication that something was rotten in the Roman Republic. A majority of historians judge the disintegration of the office during the time of the Gracchi brothers as the crack in the foundation of Republican self-government, and indeed, within three generations of this corruption, the Roman Republic completely collapsed, was incapable of handling its problems at home and abroad, and the Western world was plunged into violent despotism and dominated by the violence of competing generals.
The average person living within the borders of the "civilized" world was subject to torture, imprisonment, and violence at any time. Human morality reached its lowest ebb in 1000 years and would not be surpassed in depravity until the modern empires and totalitarian regimes nearly 2000 years later.
Where are we today? History doesn't repeat itself but we have to admit a certain family resemblance among the species at times.
The great responsibility of the Tribune was to protect the rights and interests of the citizens who did not command large armies, possess immense private resources, or deal in high-level government administration and policy-decisions which inevitably benefited certain individuals privately.
For this reason, the Tribune could not be a part of the military/economic upper class.
The founders of the United States believed that this function would be informally fulfilled by guaranteeing a "free press" in the Bill of Rights.
In their defense, they could not have foreseen the evolution of the media, the decline in reading comprehension and language, nor the advances of technology that have confounded and stunned the "average citizen," rendering him/her incapable of interacting with government or dispossessed of the desire to do so.
As experience has once again proven, the informality of this power is not enough. How do we effectively say "no" to bad government, bad laws, and bad policies, in the name of good sense?
A popular veto, might, if thoughtfully constructed into our government, allow the majority to demand honesty, information, and interaction with government decision-makers beyond the election day. We would not simply elect a dictator once every four years, but would have the ability to completely halt any policy, by voting, if we believed that it obviously contradicted the interest of a majority of Americans.
Certainly, if we can find the time to vote for the winners in a singing contest, we could surely have taken the time to vote against any number of bills contrary to the citizen's interest.