Tom makes a distinction between the Democratic ideologic leadership and the party members. Between environmentalist leader ideologs and the populace concerned about the environment.

Let me illustrate yet another such gap.
The Bishops and Cardinals of the Catholic Church covering up repeated and endemic child molestation by gay priests by just transferring them around. THEY, the Church hierarchy, do not reflect the core views of the lay churchmembers on this crime, yet they set the policy and still get some (decreasing nowadays) support from the laity.

In other words, each of these orgs (the environmental movement, the DNC, and the Church) have been co-opted by a core group that has captured the leadership yet does not really reflect the good moral concerns of their wide bodies of members.