Arnold Kling has a definition for political liberalism which is quite subtle:
After finishing the book, I came up with the following three dispositions for modern liberals.
1. A disposition to have a modest concern that increased state power over economic matters could undermine individual freedom.
2. A disposition to view unelected government officials as acting on behalf of the common good.
3. A disposition to view business leaders as acting contrary to the common good.
With respect to (1), if you replace “a modest concern” with “an overwhelming concern,” you change the liberal into a libertarian (or, for those who are picky about such things, you change a modern so-called liberal into a classical liberal.)
On the other hand, if you replace “a modest concern” with “little or no concern,” you change the liberal into a socialist.
I like this because it softens the edges and allows for many shades of gray and crystallizes differences in belief systems.