The phrase "as a crackpot" is correct and usable in written English.
It can be used to describe someone who is considered eccentric or has unconventional ideas, often in a dismissive manner.
Example: "He proposed a theory that the moon landing was staged, which many dismissed him as a crackpot."
Alternatives: "as a lunatic" or "as a weirdo".
Witness www.drducky.com., whose host (stage name, Ducky DooLittle) describes herself as a "crackpot sex expert".
He described Mr. Buttrey as "a crackpot who I currently am suing".
Some dismissed him as a crackpot, but others saw his protest in the shadow of the Mother of Parliaments as a crucial test of modern British democracy.
The resentment propelled a secession movement, which had started out as a crackpot notion, onto the 1980 ballot in six southern counties.
"It might be viewed as a crackpot idea," he said, "but it's valuable for the purpose of a dialogue on the traffic issue because there are limited solutions".
When State Senator Russell Pearce first started pushing for a law that requires police forces to stop and check anyone who appears to be an illegal immigrant, he was dismissed as a crackpot.
The students, she suggests, regard her as a bit of a crackpot.
Or do they merely qualify as local color in a crackpot paradise?
Arup Gupta, a commodities trader in Ho Chi Minh City, adds that as a consequence of a crackpot and expensive campaign in Thailand to subsidise the country's rice farmers, Vietnam is now being undercut as Thailand unloads stockpiles at bargain-basement prices.Scientists also warn that the Mekong delta, which produces about half of Vietnam's rice, is showing signs of environmental stress.
Do you want to be branded as someone who is a crackpot or someone who's an expert?
Of course, holding Lee and Ling as prisoners was also a significant propaganda victory for North Korea, insofar as the ravings of a crackpot rogue nations can be held to be significant.
