Vindictive former personnel manager

What can I do about a vindictive former personnel manager (who hates me). I keep applying for new positions (for the last 18 months) but have got precisely nowhere. Being highly skilled and suitably qualified in a specialized field of electronics, any other explanation seems unlikely I am 100% certain that this individual is giving verbal negative responses about me. Please respond.

Great Site BTW,
R

Get proof as to whether or not this manager is in fact bad mouthing you or not.
If he IS, you can sue him for defamation of character.
If you are a hard worker and are perfectly capable of doing a job, but people refuse you the opportunity to prove so because of something they heard from someone else, you're being discriminated against, and it's HIS fault.
He's wrongfully inhibiting you from gaining opportunities.
Even if a future employer at another company were to call him for a reference, he still needs to be careful about what he says and how he says it, because if he badmouths you, you can go after him for defamation of character.  Alison Graves stated the above answer.