WASHINGTON (JTA) — The Republican Jewish Coalition is spending $500,000 in Pennsylvania to protect the state’s incumbent senator, Pat Toomey.

Matt Brooks, the RJC director, told JTA on Monday that the ad campaign targeting Toomey’s challenger, Katie McGinty, had topped $500,000, twice what a political action committee affiliated with J Street, the liberal Jewish Middle East policy group, is spending to support McGinty in the state.

The RJC is running an ad on the internet and on television targeting for her support of the Iran nuclear deal; J Street, similarly, is targeting Toomey for opposing the sanctions relief for nuclear rollback deal reached last year.

The Iran deal has become a battleground this election between liberal pro-Israel groups who backed it and centrist and right-wing pro-Israel groups who opposed it. It has figured in a number of Senate and U.S. House of Representatives races.

The Pennsylvania race is tight, and among the states Democrats hope to win to regain control of the Senate.