Sen. Brian SchatzBrian Emanuel SchatzDem senator: 'Stop pretending' law banning separation of migrant families is hard to pass Hillicon Valley: Judge approves AT&T-Time Warner deal in blow to DOJ | Dems renew push to secure state voting systems | Seattle reverses course on tax after Amazon backlash | Trump, senators headed for cyber clash | More Tesla layoffs Dems question FCC's claim of cyberattack during net neutrality comment period MORE (D-Hawaii) and Rep. Colleen HanabusaColleen Wakako HanabusaOvernight Energy: Zinke defends ‘Konichiwa’ greeting | Lowe's drops cancer-linked chemical from stores | Fight between EPA, Dem over summit heats up Zinke cites ‘friends that were Japanese’ in defending 'konichiwa' greeting West Virginians thankfully rejected Don Blankenship's racist remarks MORE (D-Hawaii) are in a dead heat in their battle to win the Democratic nomination for Schatz's Senate seat, according to a new poll conducted for Hawaii's Civil Beat.

Schatz and Hanabusa each pull 40 percent support in the live-caller poll, conducted by the Merriman River Group.

The results are the latest to find a close race, though there has been a great deal of fluctuation in the difficult-to-poll state. A recent poll from Schatz's campaign found him leading by 4 percentage points, while one conducted for the Honolulu Star-Advertiser found Hanabusa with an 8-point lead.

Hawaii's politics are often driven by ethnic divisions, and this poll suggests that is continuing. Schatz, who is white, has a 54 percent to 30 percent lead over Hanabusa with Caucasian voters. Hanabusa, who is Japanese-American, leads Schatz by 47 percent to 31 percent with Japanese Americans and 63 percent to 23 percent with native Hawaiians.

Schatz has a big edge in the money race, with $2.4 million in the bank to Hanabusa's $880,000. The primary is in August.

The live-caller poll of 643 likely Democratic primary voters was conducted from Feb. 12-15 and has a margin of error of plus or minus 3.1 percentage points.