The Democratic Congressional Campaign Committee is now spending money to help defend Reps. Jim Costa (Calif.) and Raúl Grijalva (Ariz.), whose re-election bids have only recently been considered threatened, in response to the continually shifting political landscape.

With just more than two weeks before the midterm elections, the DCCC spent $40,000 on advertising in California’s 20th district, where Republican Andy Vidak is challenging Costa, according to reports filed Saturday with the Federal Election Commission.

The DCCC ad says Vidak would cut federal funding for water projects that are vital to agriculture in the central California district, where Costa is running for a fourth term. “There are some things we can’t do without,” the ad’s narrator says, referring to water. “Andy Vidak, he’s one thing we can do without.”

Grijalva’s campaign says his race in southern Arizona’s 7th district is the closest of his career. The DCCC reported spending $63,000 on an ad for the Congressional Progressive Caucus co-chairman against Republican Ruth McClung, who has recently received a flurry of endorsements from national Republican figures.

The DCCC ad targets McClung for supporting a national sales tax and eliminating corporate income taxes. “Ruth McClung. Radical ideas we can’t afford,” the ad’s narrator says.

Grijalva joins three other Democratic incumbents in Arizona in fighting off stiff challenges: Reps. Ann Kirkpatrick, Harry Mitchell and Gabrielle Giffords.

Meanwhile, the National Republican Congressional Committee began spending money in Hawaii’s 1st district, which is just the second GOP-held district that the committee has engaged. The NRCC has already invested in the open-seat contest in Illinois’ 10th district, where GOP Rep. Mark Kirk has forgone a re-election bid in order to run for the Senate.

According to reports filed Saturday with the FEC, the NRCC just spent $121,000 on behalf of Rep. Charles Djou, who won a May special election in the Oahu-based district where President Barack Obama grew up. Djou is running against state Senate President Colleen Hanabusa (D), whom Djou defeated along with former Rep. Ed Case (D) in the three-way special election.

The NRCC also reported spending money on polling in North Dakota, where Rep. Earl Pomeroy (D) is considered vulnerable, and Ohio, where the re-election of sophomore Rep. Charlie Wilson (D) is appearing less like a sure thing.