No.
In my state, both parties have county committees. These committees are made up of elected representatives from each municipality in the county.
The county committees will recruit and support the local candidates(mayors, councilmen, supervisors, auditors, dogcatchers, etc.) They usually provide fund-raising for county and state candidates - for a fee. You have to pay to play.
The DNC and the RNC will never get involved in a local race. Although, anything can happen in politics.
The State Democratic or Republican Party will typically only work to help state-wide candidates (like governor or attorney general) or state rep's or senators. Occasionally, they'll get involved in a US senate race if it's winnable for them. They aren't helpful to local candidates either.
EDIT - If you're referring to a primary race, it is customary for the party (either one) to not back a candidate, in the event that the guy that they back loses.