David Bossie, a contender to be President Trump's next chief of staff, said Tuesday that whoever gets the job must be prepared for constant battle with House Democrats.

Bossie, Trump's former deputy campaign manager in 2016, is on the short list of candidates to replace outgoing chief of staff John Kelly. He told Fox News that Democrats will be using a "subpoena cannon" to attack the White House once they take control next year, and said Kelly's replacement must be ready for that.

[Also read: Mark Meadows ended up on Trump's chief of staff short list without even speaking to him]

"A political, legislative and communications strategic person who can come in here and help him with his 2020 re-elect, as well as somebody who will be able to handle what is this subpoena cannon," Bossie told Fox News when asked what kind of person would best serve Trump.

"Somebody's who's going to understand what the House is going to do to him and the White House staff, and trying to drag them into a legal process and an investigative process that will slow down the success of this White House," he added. "Somebody who can stop that from happening."

Bossie told Fox News he has "no idea" who Trump will pick, but said he's humbled to be on the list.

"The president is going to do an incredibly methodical job, just like he always does, in figuring out who best serves him and what the next two years looks like," he said.

"I know that the president's going to pick the right person no matter who it is," Bossie added.

Bossie confirmed he is having lunch with Trump and Corey Lewandowski on Friday, but declined to speculate on whether he might be offered the job then.