Kahane soon founded a new party, Kach, which ran in the 1973 elections. The party won 12,811 votes (0.82%), just 2,857 (0.18%) short of the electoral threshold (1%) and winning a seat. The party was less successful in the 1977 elections, in which it won 4,396 votes, and in 1980 Kahane was sentenced to six months in prison for his involvement in a plan to commit an "act of provocation" on the Temple Mount. The 1981 elections were another failure, with Kach receiving only 5,128 votes.
However, events in the next couple of years increased the party's popularity. In 1982 Israel returned the Sinai Peninsula to Egypt as part of the Israel-Egypt Peace Treaty which involved evacuating Israeli settlers living in the peninsula. There was fierce resistance, particularly in Yamit, the largest settlement, where several extremists had barricaded themselves inside a synagogue and were threatening to commit suicide. Menachem Begin's government asked Kahane to act as an intermediary and convince them to give in.
Prior to the 1984 elections the party was barred by the Central Elections Committee for racism. It successfully appealed to the Supreme Court, which reversed the CEC's decision, ruling that the Knesset Elections Law (one of the Basic Laws of Israel) did not allow a party to be barred on the grounds of racism, but did suggest that the law be amended. In the elections the party won 25,907 votes (1.2%), passing the electoral threshold for the first time, and winning one seat, which was duly taken by Kahane.
In response to Kach's election and following up on the recommendation of the Supreme Court, the Knesset passed an amendment to the Elections Law, which stated:
As a result, Kach was disqualified from running in the 1988 elections by the Central Elections Committee. The party once again appealed the decision, with Kahane claiming that security needs were justification for discrimination against Arabs. This time the appeal was unsuccessful, with the court stating that the aims and action of Kach were "manifestly racist."
Following both parties noting their support of a grenade attack in Jerusalem's Old City, government minister Amnon Rubinstein asked the Attorney General to launch criminal proceedings against both Kahane and Marzel on the charges of incitement to terrorism.
In 1994 both groups were banned outright by the Israeli cabinet under 1948 anti-terrorism laws following statements in support of Baruch Goldstein's massacre of 29 Palestinians at the Cave of the Patriarchs (Goldstein himself was a Kach supporter). Many of their leaders spent time in Israeli jail under administrative detention, particularly Noam Federman, who spent more than 6 months in lockup without being indicted. Yigal Amir, who assassinated Yitzhak Rabin in 1995 was a member of Eyal (the Jewish Fighting Organization), linked to Kach and Kahane Chai and established and headed by Avishai Raviv (a paid government informant).
After being convicted for sedition for distributing pamphlets advocating violence against Arabs, Binyamin Kahane and his wife were both killed in a Palestinian ambush in December 2000.
Following the banning of Kach and Kahane Chai, the movements officially disbanded. The leadership of the former Kahane Chai formed an advocacy group known as The Kahane Movement. The group's activities consist mainly of maintaining the Kahane website, kahane.org. However, the Kahane Movement is listed on the United States' list of terrorist organizations as an alias for "Kach", though the group denies this.
The New Kach Movement existed during between 2001 and 2003 and maintained websites posting Kahanist political commentary and held meetings with informal members. Headed by Israeli-born student Efraim Hershkovits, it had chapters worldwide as well as a youth movement, Noar Meir. Upon returning to live in Israel in 2003, Hershkovits disbanded the movement to avoid harassment by the Israeli government, advising its former members to support the Kahane Movement. After the organization had disbanded, its name was also added to the United States' list of terrorist organizations as an alias for "Kach". Hershkovits was arrested on August 7, 2005 and placed in administrative detention for three months by Israeli authorities.
The State Department also says that the group is suspected of involvement in a number of low-level attacks since the start of the Second Intifada in 2000.
In the 2003 elections former Kach leader Baruch Marzel ran as number two on the Herut – The National Movement party list. The party narrowly missed obtaining a seat. In 2004 he founded the Jewish National Front, which gained 24,824 votes (0.7%) in the 2006 elections, less than half needed to win a seat.
Former Kahane Chai chief executive Mike Guzofsky continues to solicit funds in the US, with the support of US Kahanists.