Guerriero attended The Catholic University of America in Washington, DC, where he played soccer and graduated Summa cum laude in 1990.

In the House his legislative committee assignments included, Ways and Means, Ethics, Insurance, Health and Human Services, and Long-Term Debt and Capital Expenditures.

He was also an advocate for gay and lesbian issues, effecting strict anti-hate crimes legislation and increased AIDS awareness funding.

[6] Guerriero is an advocate for LGBT equality, having appeared on major television programs such as Nightline,[7] Hardball with Chris Matthews, The Today Show, and The O'Reilly Factor.

While at Log Cabin, he praised the Massachusetts Supreme Judicial Court's 2003 decision in the case of Goodridge v. Department of Public Health as a conservative ruling supporting stable families, relationships, and society, limited government, individual liberty, and religious freedom.

[18] On September 1, 2006, Guerriero became the first executive director of the Gill Action Fund, an organization working to advance gay and lesbian equality through the legislative, political, and electoral process.

During his tenure, Guerriero oversaw a national network of donors contributing more than $15 million to political campaigns and organizations in dozens of states with the aim of electing equal-rights politicians and advancing or blocking legislation.

Civitas Public Affairs Group provides bipartisan government relations, issue-based donor-giving strategies, and public-policy campaign management to individuals, non-profits, and corporations.