After all, the experience of the 20th Century was largely that the greatest threats to individual liberties (and to life) came in societies in which governments took total control of not only the state (and often the economic) sectors, but also of the details of daily life - the Soviet Union, Nazi Germany, Fascist Italy and Communist China. Whether one labeled those governments as Left or Right is probably irrelevant; the results were totalitarianism and horror.
So, why is it that "progressives," (the re-branded liberals, post the Mondale/Ferraro disaster) do not approach government expansion with the same concerns as conservatives?
After all, probably far more liberals (defined for these purposes as those opposed to limits on free speech and religion, supporters of alternative or minority political parties, advocates of unfettered artistic expression and alternative social structures, such as Socialism, etc.) went to their deaths in the Soviet Gulag and the Nazi death camps, than ever did economic or political "conservatives."
The correlation between governments that controlled almost all of a society, and the horrors of the 20th Century, is not perfect but it is very clear.
I'd think that the more cogent criticism of government expansion is not that of many conservatives: that it is costly, inefficient, likely to produce unintended consequences, destroys or punishes individual initiative and creativity, etc., all of which is often true, but that it is, from the lessons of history, a clear threat, and arguably the most potent one, to individual liberties (Ayn Rand's argument, after she moved from Soviet Russia to the U.S.)
A man from Mars might wonder why, then, today's liberals/progressives are not in the forefront of those concerned with an ever-expanding role for government in our society.