After graduating, his association with Costello continued. Working as a solicitor, he assisted Costello in winning the 1985 Dollar Sweets case. In 1987, age 30 Kroger was elected as the president of the Victorian division of the Liberal Party of Australia and was president until 1992, becoming the longest serving president in the Victorian Division's history. He instituted a series of reforms, including a move to increase the power of the party executive in preselections. While this led to several preselection challenges in 1988 and 1989, it also helped in the election of several young Victorian federal parliamentarians who are widely considered to have bright futures although, as of 2005, this pattern had not been replicated at state level. Kroger himself often turned down opportunities to run in blue ribbon Liberal seats, notably Kooyong in 1994 and in Goldstein in 2004, preferring to concentrate on family and business interests. From the 1990s the Victorian division of the Liberal Party was factionalized between Kroger's supporters and those of the more conservative former Premier, Jeff Kennett. This has led to some bruising preselections, such as the Kennett-backed Louise Asher defeating the Kroger and Costello-backed Mitch Fifield in Brightonin 1999. However, both backed Petro Georgiou when he was challenged for his preselection by Josh Frydenberg in 2006. However, Peter Costello is no longer factionally aligned with Kroger. In 1993 Kroger established an investment company, JT Campbell & Co, and currently serves as chairman. He has also spent five years as a director of the Australian Broadcasting Corporation. In May 2012 he very publicly expressed concern over matters relating to Peter Costello's apparent idea of returning to the Federal Liberal parliamentary party. Kroger's former wife, Helen Kroger, was demoted on the Liberal Party senate ticket and was almost facing a challenge by some Liberal for the Senate whip position. Costello has said that Kroger asked him for help regarding Helen Kroger's troubles with the Liberal party, though Costello decided not to help. Kroger was nominated to become state president of the Victorian Liberal party for the second time. Tony Snell stood down as state president at the Liberal state council in March 2015 and Kroger was elected his successor. Kroger was challenged in 2017 for the Liberal party presidency by Peter Reith. Reith suffered a stroke prior to the vote, and it did not proceed. In April 2018, Marcus Bastiaan was elected metropolitan male Vice President of the Liberal Party at the party's annual State Council. Michael Kroger retained the party presidency by a vote of 721-448 against former Vice President Greg Hannan. In 2018, Kroger declared his intention to not seek another term as Liberal President. He retired as State President of the Liberal Party on 30 November 2018.
Private life
Kroger’s first wife Helen Kroger was elected to the Senate for Victoria at the 2007 election after being preselected in the safe second position on the Liberal ticket, along with the aforementioned Mitch Fifield and number three candidate Scott Ryan. Senator Kroger lost her Senate seat at an election in 2013 and in 2016 for the seat of Bruce. Despite their divorce, Michael and Helen remain close friends and are considered to be political allies. Kroger married Ann Peacock, daughter of Andrew Peacock and Susan Renouf, in March 1999 at St Michael's Uniting Church, in Collins St, Melbourne. They separated in 2009.
