Just in time for upcoming elections, Google has released an AdWords feature that lets political candidates (and anyone else, for that matter) target their campaigns by Congressional District.

Given how difficult it is to pinpoint audiences within particular districts by ZIP code or municipality — and the fact that district boundaries change every 10 years — the capability should be very welcome, especially since all House members are up for reelection this Fall, following redistricting that took place after the 2010 census. To create the feature, Google partnered with Azavea, which provided it with the data to find the Congressional Districts.

In a blog post, Charles Scrase of the Google politics & elections team said the company was dedicating substantial resources to courting political campaigns: “We’ve built a sizeable team that is working around the clock to help all candidates get the most from their online advertising efforts.”

As an example of the feature’s value, Google cites the oddly-shaped 6th Congressional District in Maryland, which doesn’t jibe with any particular TV markets.

Though AdWords has long been a mainstay in national and state-wide campaigns, this feature should allow Google to play a more significant role in Congressional races. Political site Politico says the new capability will be a boon for candidates that may not have had a large enough budget to advertise on TV.