Former FBI Director James Comey said President Donald Trump's move to separate migrant children from their parents could be the biggest mistake of his presidency.
Under huge pressure from Democrats and Republicans alike, Trump hastily reversed the policy Wednesday.
"Every so often, the giant is awakened that offends no matter where you are. There's good to come out of it (migration policy), it may be stirring the giant," Comey told a London audience on Thursday. "That's why Trump ran so fast and lied so much. One thing he is good at is sensing the giants awakening."
The White House did not immediately respond to a CNBC request for comment about Comey's remarks. It released a statement on Wednesday blaming congressional inaction for the separations, saying that it is "the policy of this administration to maintain family unity, including by detaining alien families together where appropriate and consistent with law and available resources."
According to Pew Research Center data published Wednesday, voter engagement is higher than in previous midterm election campaigns.
Comey, a registered Republican at the time of the 2016 election, said he will vote based on values rather than party affiliation in 2018.
Slamming Trump multiple times on his personality and his strategy, Comey described his ideal candidate as one whose values are the opposite of Trump's.
"The next president has to restore truth, rule of law, and equal protection of law, things at the heart of the U.S.," Comey said.
Comey didn't reveal which political party he would vote for, but he talked a great deal about the values they should have in contrast to Trump.
Though Comey had much to say about the man who fired him last year, he also said the Justice Department inspector general was correct in finding his actions as FBI director "extraordinary and insubordinate" — but not politically biased — in the Hillary Clinton email investigation.
Comey is due to teach on ethical leadership this fall at the William & Mary Law School.