CQPolitics.com: When Henry A. Waxman tries to get a global warming bill out of his House Energy and Commerce Committee this spring, much will depend on the views of moderate and conservative Democrats whose votes could be critical in moving the legislation forward. After Waxman, D-Calif., took over the committee chairmanship this year, environmentalists welcomed what they hoped would be a major shift in outlook compared to the former chairman, John D. Dingell , D-Mich. Dingell, who has close ties to …