The book "The Forth Revolution" [1] has a really good history of how the size of the state has exploded globally since the 1950s. The push for greater and greater power has been a global phenomenon. It has continue almost unabated, the rhetoric of the right such as Reagan/Thatcher in the 1980s was merely a small blip in the hockey stick growth.
> The first revolution was the rise of the European nation-state after the Peace of Westphalia; the second was the late-18th- and 19th-century turn toward individual rights and accountable government; the third was the creation of the modern welfare state. Each revolution improved the state’s ability to provide order and deliver vital services while still fostering innovation. But as democratic publics demanded more and more, the state promised more and more, eventually overextending itself. In Revolution 3.5, Margaret Thatcher and Ronald Reagan tried, but failed, to shrink the state.
The second half of the book is less good where it predicts the eventual shrinking of the state towards an efficient Singapore-esque limited government (aka the fourth revolution). But they make very good observations about the current state where individual liberties are continually diminished, innovation is crippled, widespread government inefficiency is the norm ("94% of government IT projects failed in last decade"), budgets are bloated, and the economic growth needed to support social services stalls.
The cause may simply be that whenever a crisis happens everyone calls for something to be done, then laws get passed, regardless if they are effective or not (see: terrorism, drugs, etc) as well as the thousands of small regulations over business every time someone gets hurt or dies or were merely pushed through by incumbents protecting their market share. Combine that with constant crises over a couple decades and you have quite the large administrative state.
But I think it may be more simply the result of the "The Iron Law of Bureaucracy" [2]. As organizations mature, without push-back, administrators end up taking over every aspect of an organization (happened at universities too) and the administrators favourite thing to do is creating new rules requiring more administrators. Which is how you end up with so many government agencies that they don't even know how many exist in the US [3].
The growth of the modern state is hardly a partisan issue, at least not in practice.
[1] https://www.amazon.com/Fourth-Revolution-Global-Reinvent-Sta...
[2]
http://www.jerrypournelle.com/reports/jerryp/iron.html
[3] https://cei.org/blog/nobody-knows-how-many-federal-agencies-...