Sen. Susan Collins, who announced on the Senate floor Wednesday that she would oppose President Donald Trump’s nominee to lead the Department of Education, applied a simple, but precise standard for cabinet nominees. Do they understand and support the mission of the department they are slated to head? Betsy DeVos, a billionaire champion of private and charter schools, failed that test in Collins’ estimation.

In announcing her decision, Collins was the first Republican senator to oppose a Trump nominee. She was soon joined by Alaska Sen. Lisa Murkowski. Sen. Angus King, an independent, announced last week that he would oppose the DeVos nomination. All Democrats in the Senate are expected to oppose DeVos. If no more Republicans join Collins and Murkowski in the final Senate vote, DeVos would be confirmed with Vice President Mike Pence casting the 51st, tie-breaking vote.

This vote, as all cabinet confirmation votes, should not be about partisan politics. The decision on DeVos isn’t about whether school choice should be expanded, as many Republicans want. Rather, it is about whether DeVos is qualified to oversee the federal agency responsible for public education.

DeVos’ troubling lack of knowledge about public education and federal education laws, especially those pertaining to children with disabilities, was evident as she answered questions before the Senate Committee on Health, Education, Labor and Pensions last month.

Based on what she heard during that hearing, during a meeting with DeVos and in correspondence with her, Collins concluded that a “no” vote on the nomination was the principled choice. This was reinforced by the numerous phone calls and conversations the senator had with constituents who shared concerns about DeVos’ ability to be a champion for public education.

“The mission of the Department of Education is broad, but supporting public education is at its core,” Collins said on the Senate floor. “I’m concerned that Mrs. DeVos’ lack of experience with public schools will make it difficult for her to fully understand, identify and assist with those challenges, particularly for our rural schools in states like Maine.”

“I will not, I cannot vote to confirm her as our nation’s next secretary of education,” Collins concluded.

The standard Collins applied to DeVos — supporting the mission of the agency she is nominated to head — should also be applied to Trump’s nominee to head the Environmental Protection Agency, Scott Pruitt. We are encouraged that Collins has raised these concerns about Pruitt. She is the only Republican to do so.

As attorney general of Oklahoma, Pruitt has been openly hostile to the EPA’s mission of protecting human health by regulating dangerous pollutants, such as mercury and carbon dioxide, a major contributor to climate change. He has filed more than a dozen lawsuits to stop EPA regulations, many of which Collins has championed.

Pruitt is especially beholden to businesses, particularly in the fossil fuel sector. He regularly accepted industry-drafted letters and talking-points as his own, a lengthy New York Times investigation from 2014 documented.

Someone who has repeatedly tried to prevent the EPA from doing its job surely should be disqualified from overseeing the agency.

The BDN Editorial Board

The Bangor Daily News editorial board members are Publisher Richard J. Warren, Editorial Page Editor Susan Young, Assistant Editorial Page Editor Matt Junker and BDN President Todd Benoit. Young has worked...