The vessel was attacked after Iran warned ships must use its designated corridors through the Strait of Hormuz rather than the route the U.S. has backed.
Democrat Blake Gendebien is in a dead heat with Republican Anthony Constantino in a deep-red upstate New York congressional district, internal poll shows.
The relatively warm reception to the Homeland Security secretary is notable given past Democratic skepticism about Mullin's promised efforts to mend fences with Capitol Hill.