could not get elected dogcatcher

Dogcatchers are virtually never elected to their posts; the phrase is hyperbole, using dogcatcher to indicate the most lowly conceivable office.

• "An insolent Republican newspaper asserts that Mr. [Grover] Cleveland is so unpopular in Washington that he could not be elected dog catcher for the district. This may be true, yet Mr. Cleveland has caught a great many dogs in his day—stealing. His success in that line would naturally make him unpopular with the claims agents and other parasites that throng the capital."
• "It is a well known fact that the average American town will not elect well educated men to municipal offices if they can help it. A man who wears kid gloves and a plug hat couldn't be elected dog catcher in any town in Oklahoma. That is why the affirmative wish the city manager to be elected by a commission."
• "Men like him couldn't get elected dogcatcher. He was a natural lieutenant, not a leader, and it was a fact he accepted with neither bitterness nor regret."
• ""She [Christine O'Donnell]'s not a viable candidate for any office in the state of Delaware," said the state party chairman, Tom Ross, who is backing [Mike] Castle. "She could not be elected dog catcher.""
• "[Donald] Trump, who has a glancing relationship with the truth and speaks English only as a second language, has hurled his insults at [Bob] Corker (whom he said couldn't get elected dog-catcher in his home state) and at [John] McCain – even as he journeyed to Capitol Hill to try to build support for tax reform."

• unelectable
• run like a dry creek