Hsu then returned to the United States in the late 1990s, despite his fugitive status, and established several addresses in the San Francisco and Los Angeles areas. He became an investor in Silicon Valley, invested in real estate in the San Francisco Bay Area, and still had engagements in the garment industry. He later relocated to New York, where he seemed to become involved in the apparel business once again and lived in a luxury apartment in SoHo while flying chartered jets.
Starting in 2003, Hsu began contributing to, and collecting contributions for, the Democratic Party, although he did not join the party and was not registered to vote. He also donated to causes such as the Innocence Project and Clinton Global Initiative. He also became a trustee of The New School in New York, to whom he donated $100,000 and provided the money for a scholarship. Democratic Party figures did not know much about him or his businesses, but appreciated his support; he became known to them as someone who could quickly raise large amounts of money, and as someone who networked tirelessly and always found ways to be included in high-profile events. By 2007, Hsu's status within Hillary Rodham Clinton's 2008 presidential campaign had risen to the level where he was a "HillRaiser", someone who had "bundled" more than $100,000 for her campaign, and to where he co-hosted a $1 million fundraiser at wealthy Democratic Party supporter Ron Burkle's Beverly Hills estate, and in September, he was scheduled to co-host a major gala fundraising event featuring music legend Quincy Jones.