Former head of US border security says claim ‘terribly misleading’ and statistics show nine of 10 convicted traffickers are US citizens

A former head of US border security has accused Donald Trump of “exploiting” the pain of the opioid epidemic to wrongly vilify migrants as responsible for the surge in American deaths from fentanyl during recent years.

But the Trump campaign is expected to double down on the deception now that the vice-president, Kamala Harris, whom Republicans describe as Joe Biden’s “border czar” and accuse of inaction over a surge of illegal immigration, is likely to be the Democratic presidential candidate in November.

Gil Kerlikowske, who led Customs and Border Protection (CBP) during the Obama administration following five years as the White House chief of national drug control policy, said Republicans know there is no truth to accusations that migrants crossing the Mexican border illegally are carrying the bulk of fentanyl sold in the US. Yet that was a line again pushed at last week’s Republican convention. Official statistics show that nine in 10 convicted fentanyl traffickers are US citizens.