According to enotes, (2018), Horizontal policy-making exists when departments of similar rank within the organizational hierarchy work collaboratively towards a common outcome. Many parties get involved in policy formation.
This checks and ensures that there is balance system benefiting the public in knowing one rogue elected President cannot make decisions without accountability. This is because one of the main responsibilities of elected leaders is to represent the interest of the people.
Congress holds the President accountable for his or her actions. Each branch of government has some way to hold the other branch accountable.
Therefore, there is hierarchy ensures that there is flow of power and connection within these branches of the government such the executive, legislature and the judiciary.
References
Enotes.com (2018). "What is the different between Horizontal and Vertical Policy Making?"
Legaldictionary.net (n.d.). Checks and Balances. Three Branches of Government Retrieved from