A long line of environmental activists, coal mine workers and others awaited Oklahoma Attorney General Scott Pruitt at the senate hearing to confirm his appointment as administrator of the U.S. EPA on Jan. 18.

Pruitt will face the Senate Committee on Environment and Public Works, which will decide whether to send President-elect Donald Trump's pick to lead the EPA to the full senate. Should he be confirmed, the nominee is expected to lead Trump's pledge to roll back regulations.

Given the limited seating available in the hearing room, voices could be heard from outside its doors asking security to "let the public in." Two protesters, one dressed in mining gear and the other holding up a sign opposing Pruitt, were removed from the room early on for disrupting the proceedings.

Heading into the hearing, Height Securities analysts said Pruitt's confirmation was likely, given his broad support from Republicans as well as at least one Democratic senator, Joe Manchin of West Virginia, willing to cross the aisle and vote in favor of the confirmation.

But Height also said Pruitt's past criticism of the Renewable Fuel Standard could be a concern for Republicans, particularly those representing Midwestern states. Pruitt has spent the past several weeks reassuring those senators, including Iowa's Chuck Grassley and Joni Ernst, according to Height. Ernst is a new member of the EPW committee, and Pruitt's hearing will be her first hearing in this new position.

Noting Pruitt's opposition to the Clean Power Plan, which addresses carbon emissions from existing power plants, FBR & Co. analysts expected to hear the nominee's plan to abandon the regulation, as well as his stance on court deference. Pruitt also will likely discuss a rule related to the Clean Power Plan that establishes new source performance standards for fossil fuel power plants.

Pruitt would be expected to reject enforcement of the Clean Power Plan should it survive an ongoing court challenge and could also tackle the underlying endangerment finding that provided the EPA with the mandate to regulate greenhouse gases, the FBR analysts said.