He ran again the first SAR Legislative Council election in 1998 he was re-elected with Lau Chin-shek on the same ticket with 55 percent of the popular vote in Kowloon West. He has specialised in the security issues, having been the party's spokesman on security issue and chaired the Panel on Security, one of the key committees in the Legislative Council. He had closely followed the works of the Independent Commission Against Corruption, immigration issues, Vietnamese refugees, crime and triads. He also campaigned for the setup of the Independent Police Complaints Commission against police abuses of power. Due to his Christian belief, he was known for his anti-gay rights voting records despite his pro-democracy political affiliation. He was re-elected in Kowloon West in 2000, 2004 and 2008. In June 2010, he expressed open skepticism of the Democratic Party's support for the government's 2012 constitutional reform package but nevertheless toed the party line and voted for the measure. In the reform package, the party had secured the inclusion of a late amendment to hold a popular vote for five new District Council functional constituencies. In a dissenting speech to Legco, he warned of the creation of "super-functional constituencies" with an apparently larger mandate than that of geographical constituency lawmakers. Nonetheless, in the 2012 Legislative Council election, he represented the party to run in the newly created territory-wide District Council constituency. His ticket received 316,468 votes in total, the largest votes in the electoral history of Hong Kong until it was exceeded by his party colleague Kwong Chun-yu in 2016.
2016 election and caucus convenor
In 2016, he was re-elected in the District Council constituency with a sharp decline of vote due the strategic voting of the pro-democracy voters who turned to vote for Kwong Chun-yu who was trailing behind To. As a result, To took the marginal seat with 243,930 votes, only 10,694 votes, 0.6 per cent higher than the unelected pro-Beijing candidate Wong Kwok-hing of the Hong Kong Federation of Trade Unions. He became the most senior member of the Legislative Council, after Albert Ho retired from the legislature and Lee Cheuk-yan was surprisingly unseated, and became the last Legislative Council member from the "Class of 91", pro-democrats who first were elected in the first Legislative Council direct election in 1991. He also became the only legislator who has been directly elected in all elections since 1991 in the most senior member in the house. In October 2016, he became the convenor of the reorganised pro-democracy caucus.
Personal life
In January 2008, To divorced his wife Cherry Yuen Choi-lin, over her alleged extramarital affair. They did not have any children. On 12 December 2009, he married Sue So. The couple have a son in 2012.
