When you look at the last month before Kirk was assassinated, he had alot of confrontations with Zionists because his stance on the occupation of Gaza and a possible war with Iran was slipping from what they found acceptable. This isn't just speculation, I watched a video where he was complaining about this with Megan Kelley about a month before he was shot.
There's a conspiracy theory that Mossad may have been involved in Kirk's death, and after the fact Netenyahu declares him a "martyr" for Zionism to regain control of the narrative. Kirk had a big influence over young Republican voters who are increasingly turning against Israeli occupation of Gaza, and Israel couldn't, in their estimation, afford to lose control of the narrative.