They’re senior senators from two of the nation’s top oil-producing states, longtime friends who are about to begin a partnership that has environmentalists uneasy and industry lobbyists counting on a shift in energy policy. Democratic Senator Mary Landrieu of Louisiana will take the gavel at the Senate Energy and Natural Resources Committee as early as today, joining Senator Lisa Murkowski of Alaska who is already the panel’s top Republican. The combination could boost industry priorities like expanded exports of oil sought by producers such as Exxon Mobil Corp. , and of natural gas sought by Dominion Resources Inc. and Cheniere Energy Inc. , as well as TransCanada Corp.’s proposed Keystone XL pipeline. “Over time, these two are going to be a pretty powerful force for energy producers and for pipelines,” said Michael McKenna , a Midlothian, Virginia, lobbyist whose clients include Treaty Energy Corp. , a Houston-based oil and […]