RepubLikud is a name for the perception of converged interests of the United States Republican Party of the United States and the Likud Party of Israel. It seems to have been coined to separate debates about Zionism from debates about imperialism, by analysts sympathetic to Zionism but not to imperialism and in particular not to oil imperialism. These see the neo-conservative movement as having an American and an Israeli element that expresses itself in control of these two political parties.
See "RepubLikud" summary of analysis in Disinfopedia, which is in context of neoconservative thought.
Summarizing, from that analysis (adding links to Wikipedia articles):
"In effect, by simply refusing to make land concessions or even implement the long-standing UN order to withdraw to the 1967 borders of the West Bank, Likud can leverage Republican Party support for an endlessly escalating military and technological conflict from which its own members, and elites of the Republican Party, directly benefit. If dangerous technology leaks out to enemies, such as the nuclear technology to Iraq or biological technology to Iran, this can provide excuses for "crackdowns" and pre-emptive war. Refusal to actually limit the development, deployment and use of such technology is another cornerstone of Republikud: G. W. Bush has withdrawn from a vast array of international agreements to control technologies, and Israel has consistently refused to allow UN weapons inspectors to review its rumoured nuclear facilities."
Critics of this analysis claim: