One could respond that big government and the welfare state inevitably threaten traditional cultural values. But it's also been argued that globalization, commercialism, and corporate power likewise threaten social and cultural traditions.
The question of just what "social conservatism" is, has to be a live question, not a matter of partisan dogma. British debates over just how "socially conservative" Thatcher and Blair are reflect the complexities of the topic.
And a tolerant respect for those traditions that make it possible for us to work together and keep society going also has to be included in "social conservatism." The author has a laudable respect for institutional traditions and social concord that many who are more activist and determined in their political views neglect.
But being "social conservative" has to mean more than being a good mixer or a faithful spouse. Someone who is "personally opposed to abortion" but committed to a "woman's right to choose" isn't really a social conservative, as the word is understood in contemporary America. Someone who encourages or winks at immorality can't be a "social conservative" according to the established understanding either.
It's not necessary to persecute those whose practices deviate from the norm. I wouldn't regard that as a part of "social conservativism." But one does have to uphold moral standards in one's own life and recognize their importance in the public sphere.
There are personally decent and personally corrupt figures in public life. The former are preferable by far. But some of our recent social troubles can be attributed to personally moral people who failed to uphold public standards.
Our language ought to reflect the fact that in addition to the public morality of fiscal integrity and the purely private morality of one's own sexual conduct, there are social and familial mores that public figures ought to promote, encourage and defend. The author's language doesn't recognize this sphere.
Arnold may be a decent guy and a good family man, but calling him a "social conservative" tends to rob the expression of meaning. things a little, one can imagine John Kerry or Hillary Clinton qualifying as "social conservative" under the author's definition, and when you reach that point, there's no point in using the expression at all.