While his recently departed predecessor, Gen. John Kelly, often tried to restrain President Donald Trump, Mulvaney — who has said he won’t seek to be a check on the impulsive president — has been egging on the president in his confrontation with congressional Democrats over a border wall.

Mulvaney is among the top officials counseling Trump to reject any short-term funding bill to re-open the Department of Homeland Security, the agency responsible for constructing the president’s long-desired border wall, said one source close to Mulvaney and one administration official. That position has made many congressional Republican leaders nervous even as it thrills Trump’s conservative base.

Mulvaney “views his role as reminding the president this is a bad deal,” said the person close to Mulvaney. “Democrats would like to try to increase spending on anything but the wall.”