The Executive branch needs to stay on their side of the tree.

EPA veteran Gina McCarthy was one of three nominees Obama announced at the White House late Monday morning.

Throughout her career McCarthy has implemented policies that attempt to constrain the use of reliable energy sources. ... It appears the president is rewarding these efforts by increasing her ability to implement an ideological and political agenda. If confirmed as EPA administrator, McCarthy will continue the regulatory attack on oil, coal and natural gas with the result that Americans will experience increasing energy costs and high unemployment rates. (Source: Fox News Report)

So it looks like the EPA will be used to bypass Congress in this administration's attempts to push forward with their climate agenda. The Executive branch needs to stay on their side of the tree.

Kind of reminds me of the illustration below.