There a couple of reasons for this but here I will discuss one of the reasons.
If you've ever wondered why government policy on a city, state or federal level never seems to actually change no matter who you vote for and what they've promised to do, the reason is that elected politicians, no matter whether legislative or executive do not actually operate government functions on a day to day basis. The real work of this sort is carried out by the people who work in the managerial bureaucracies (see the 8 Laws of Bureaucracy).
Bureaucrats are unelected and unaccountable to the citizens, despite legislative oversight and being at least technically beholden to the elected executive. Due to being tenured, it is difficult, if not impossible to fire, a bureaucrat for failing to implement policy changes they disagree with and will serve out careers longer than many electeds, thus outlasting the elected's policies. Government policy can therefore not change unless the managerial bureaucracy permits it or unless the electorate elects to office enough legislators and executives who will actively work to bring accountability to policy and control the bureaucracy.
Bureaucrats, who on the average adhere to a certain political dogma or are of high enough rank, who disagree with policy changes have ways of thwarting these changes ranging from dense, jargon laden testimony before legislators and the media highlighting their unquestionable expertise to dragging their feet in implementing or simply refusing to implement policy changes. Bureaucrats tend to be liberal but civil service also tends to attract leftist social justice warriors looking for a venue through which they may implement their agendas and actively thwart conservative agendas with the protection of tenure and unions.
All bureaucrats, ideological or time serving civil servants, have since the New Deal taken on a vision of themselves as the caretakers of the American people who are but little more than idiot dependents. The bureaucrat therefore believes that he knows what is best for the country and must act against the popular will to protect the people from themselves.
This means that the managerial state must lie to the people to placate them and quiet them down as one would with a noisy child while the technocrats enact policies that in their opinion is the best thing for all concerned. If the American people disagree and want something different done, then tough shit kid. We know best, we are in charge so sit down and shut up when your betters are talking and stay out of your better's way when they're working. As Sam Francis noted, in the managerial state, the American people may have a vote but they do not have any power.
As it stands now, managerial bureaucracy in at least the upper-middle, upper management and like the elected political class have become a de facto ruling class increasingly socially isolated from the average American citizen over which they govern with few newcomers admitted without the proper Ivy League credentials and proof of loyalty to the ruling class agenda. Isolated to the point where they no longer view the average citizen as their fellow countrymen as they now belong to a cosmopolitan ruling class whose only concern is promoting their own class interests.
The solution to this should be to think heuristically. If the only power we have is the vote then we must use that vote to support insurgent candidates who will promise to curb the power of the managerial state even if they are not perfect. If the Overton window is forced further right, away from the ossified collectivism of the left, it will break the stranglehold the social justice warriors have over free and open debate and pave the way to taming the beast. Not to completely kill the beast as some degree of managerialism is necessary to operate a modern government but to compel the managerial bureaucracy and elected politicians to abandon their ruling class pretensions and act in the best interests of our country and her citizens.