The phrase "run headlong" is correct and can be used in written English.
It means to run quickly and without hesitation, often with great force or intensity. Example: The thief ran headlong through the dark alley, trying to escape from the pursuing police officers.
That recommendation would probably run headlong into the immigration debate in the United States.
But in this case, as some of Mr. Bush's advisers acknowledge, that logic has run headlong into other priorities.
Their efforts have run headlong into the increasingly powerful economic incentives behind poppy growing, whereby one acre of land can produce more than $4,000 worth of opium.
But the minute the crocuses bloom and shad run headlong against cold currents, the pressure is on from diners weary of root vegetables.
The lanky lines of this first poem run headlong into the margins of the unusually wide pages of the new Graywolf edition.
Across the room, Virginia tried to calm a man who had refused to take his medication and was threatening to run headlong into traffic.
In the words of JoongAng Ilbo, a widely read South Korean daily, "Our nation has run headlong toward the goal of becoming wealthy.
The administration's rule has now run headlong into a dispute over values as Republican presidential contenders compete for the most conservative voters.
Promises of high-altitude luxury may run headlong into the economic rationale for the A380, which is its ability to haul 555 or more passengers.
President Bush would like that, but he has run headlong into opposition in Congress, much of it from within his own party.
It was as though Uncle Remus had run headlong into Clive Barker, with Ku Klux Klan grand wizard David Duke serving as creative consultant.
