Why isn't Communitarianism more popular as an ideology?

[Bluegrass Cruiser 420]

Because, especially in recent decades, the vast majority of Americans tend to value individual freedom over collective action; though we may differ as to the actual definition of 'freedom'.

However, many modern day Republicans, especially ones like Huckabee, are increasingly communitarian/populist. Also, the Democrats used to have a very strong populist wing (especially in the South).

I would agree with that assessment.  That is also why the left has to be careful when it tries to fashion a so-called religious left. That whole concept is basically taking socialism and dressing it up in religious drag to appeal to people who have a genuine faith in say, a Christian religion of some domination or another.  If they overdue it a lot, people in this country will likewise see it as too much mixing of church and state.

[Bluegrass Cruiser 420]

Americans don't want European styled social democracy.  But they're quickly seeing that the traditional fetish for Jeffersonian/Jacksonian for small government isn't necessarily the best way to get things done.

Well I would agree that Americans are moving away from traditional ideals of limited government.  That is why politicians are always looking for the right issue to propose a new government programs for that they can cynically exploit it for votes without really solving the problem.

I whatever those politicians choose to call their beliefs it won't be social democracy but they call it progressive, populist or maybe even communitarian (if focus group data tells them that people like the sound of that term).