Pro-Israel groups are wading into a Republican congressional primary, marking a departure from their recent focus on attacking progressive candidates and offering the latest test of the pro-Israel lobby’s strength as the war in Gaza weighs heavily on voters’ minds.The former Indiana congressman John Hostettler, who served in the House from 1995 to 2007 and will compete in a crowded primary on Tuesday, is looking to return to the chamber to represent the state’s eighth district. Hostettler’s allies praise him as an “America first conservative” who will help terminate financial aid to Ukraine, so his primary will also test Republicans’ embrace of isolationism, which has gained popularity in the party amid the rise of Donald Trump. But Jewish groups have criticized some of his past comments about the start of the Iraq war as antisemitic.Hostettler’s victory is far from assured, as seven other Republicans have launched primary bids and outside groups have already poured millions of dollars into the race.According to documents filed with the Federal Election Commission, the United Democracy Project (UDP) Super Pac, which is affiliated with the American Israel Public Affairs Committee, has spent $1.2m against Hostettler. The Republican Jewish Coalition (RJC) Victory Fund has also spent about $950,000 supporting one of Hostettler’s top rivals, the Indiana state senate majority leader, Mark Messmer.Those figures dwarf Hostettler’s own fundraising numbers, as his campaign has reported bringing in $40,635 in donations across the election cycle to date. Messmer brought in nearly 20 times as much, reporting $763,290 in contributions so far.The UDP ad attacks Hostettler as “one of the most anti-Israel politicians in America”, excoriating his past voting record in the House. Both the UDP and the RJC have specifically criticized Hostettler for his vote opposing a resolution expressing solidarity with Israel in 2000, after the start of the second intifada, as well as the comments he has made about the origins of the Iraq war.In his self-published book, Nothing for the Nation: Who Got What Out of Iraq, Hostettler criticized former president George W Bush for relying on foreign policy advisers “with Jewish backgrounds” in the lead-up to the war, arguing those officials were too focused on the fate of Israel. One review, published by the Jewish Standard in 2008, accused Hostettler of perpetuating “age-old slanders of Jewish disloyalty to their countries”.“We are deeply troubled by John Hostettler’s past record, and RJC is committed to ensuring he does not get back to Congress,” the group’s CEO, Matt Brooks, said last month. “Hostettler has consistently opposed vital aid to Israel, trafficked antisemitic conspiracy theories and voted against a 2000 resolution which supported Israel.”The UDP’s investment in Hostettler’s race marks a notable shift in its spending this election cycle, as the group has largely focused on Democratic primaries so far. In California’s 47th congressional district, the UDP spent $4.6m opposing the Democratic candidate Dave Min, who ultimately advanced to the general election. The group has also spent $2.4m backing the Democrat Sarah Elfreth in the third district of Maryland, which will hold its primaries later this month.The UDP ad against Hostettler also differs from those against progressive candidates such as Min, as it focuses on Hostettler’s approach to Israel. In Democratic primaries, UDP ads have largely highlighted progressive candidates’ personal weaknesses, such as Min’s drunk-driving arrest last year.The choice to highlight Hostettler’s voting record on Israel reflects how Republican voters generally view the Netanyahu government in a more favorable manner than Democrats and independents do. A Guardian review of the statements of members of Congress after the start of the war found that every Republican in Congress was supportive of Israel. According to one Gallup poll conducted in March, 64% of Republicans approve of Israel’s military actions in Gaza, compared with 18% of Democrats and 29% of independents who said the same.skip past newsletter promotionafter newsletter promotionAlthough Hostettler faces an onslaught of spending from pro-Israel groups, other outside organizations have come to his aid in the primary. Two Super Pacs – the American Leadership Pac and the Protect Freedom Pac – have spent more than $790,000 combined to promote Hostettler’s candidacy.But other outside groups have rallied around his opponent Mesmer; the America Leads Action Super Pac has spent roughly $2m opposing Hostettler and more than $100,000 supporting Mesmer. A campaign ad from America Leads Action accuses Hostettler of advancing reckless fiscal policies during his time in Congress.America Leads Action is backed by the wealthy conservative donors Jay Faison and Rob Walton, who is a son of the Walmart founder, Sam Walton. The group has previously spent millions opposing other Republican primary candidates viewed as potential liabilities in a general election, such as Mark Harris of North Carolina and Brandon Gill of Texas.Both Harris and Gill went on to win their primaries anyway. More