In their testimony in the House impeachment inquiry, a number of key witnesses have chosen to highlight a common trait: Their immigrant backgrounds.

One came from northeast England. Another came from the former Soviet Union. Another was born in Canada to parents who’d fled the Soviet Union and Nazi Germany.

Several chose to share details of their families’ stories as they testified in front of Congress this week.

Former White House national security aide Fiona Hill, talks about the time her mother gave her a bowl haircut when she was a child as she testifies before the House Intelligence Committee on Capitol Hill in Washington, Thursday, Nov. 21, 2019, during a public impeachment hearing of President Donald Trump's efforts to tie U.S. aid for Ukraine to investigations of his political opponents.(AP PhotoSusan Walsh)

Former White House national security aide Fiona Hill, talks about the time her mother gave her a bowl haircut when she was a child as she testifies before the House Intelligence Committee on Capitol Hill in Washington, Thursday, Nov. 21, 2019, during a public impeachment hearing of President Donald Trump's efforts to tie U.S. aid for Ukraine to investigations of his political opponents.(AP PhotoSusan Walsh)

Former National Security Council staffer Fiona Hill, for instance, said the U.S. offered opportunities she “never would have had in England” because of her working-class accent.

And Lt. Col. Alexander Vindman said he felt compelled to enlist to repay the U.S.

Their stories serve in contrast President Donald Trump, who has often depicted immigrants as a threat to national security.