This article suggests that anti-WalMart is not good politics, except maybe for getting nominated as a Democratic candidate.

Three-in-four voters say attacks by politicians on Wal-Mart won't affect their voting behavior. But among those who say it will, those people are much more likely to vote against a candidate who skewers Wal-Mart than they are to vote for him

A plurality of voters also believes that Democrats who attack Wal-Mart are doing so to curry favor with organized labor, which is unhappy with the firm because its stores are non-union.

[N]ot only do these voters shop there, they overwhelmingly see the company as a positive force in their community, and by a solid margin as a good thing for the country.