From 1994 to 1995, Kirk worked as the secretary of state of Texas, until he was elected as the mayor of Dallas, where he served from 1995 to 2002 and was the first African-American to hold either of those positions.

[8] In 2002, Kirk resigned as mayor of Dallas in order to run for the Senate seat vacated by retiring Republican Phil Gramm.

Later he was a partner with the Houston-based law firm Vinson and Elkins, where, according to Texans for Public Justice, he was, as of March 2007, one of the four highest paid lobbyists for Energy Future Holdings Corporation.

[14] The U.S. Senate confirmed Kirk as United States Trade Representative on March 18, 2009, with a vote of 92 in favor and five opposed and he was sworn in the same day.

[19][20][21] Kirk has been cited as the U.S. agent who convinced South Korea to adopt and enforce an early draft of the secretly negotiated Anti-Counterfeiting Trade Agreement (ACTA).

[citation needed] The impacts in South Korea have been dramatic; tens of thousands of citizens have had their websites taken off of the Internet because of copyright infringement.

[citation needed] In May 2012, a group of 30 legal scholars, critical of the USTR's "biased and closed" Trans-Pacific Partnership (TPP) treaty negotiation process and proposed intellectual property-related provisions, publicly called upon Kirk to uphold democratic ideals by reversing the "dialing back" of stakeholder participation and to release negotiating texts for public scrutiny.

The law professors claimed that leaked documents show that the USTR is "pushing numerous standards that [...] could require changes in current U.S. statutory law" and that the proposal is "manifestly unbalanced—it predominantly proposes increases in proprietor rights, with no effort to expand the limitations and exceptions to such rights that are needed in the U.S. and abroad to serve the public interest".

[22] Kirk initially responded that he was "strongly offended by the assertion that our process has been non-transparent and lacked public participation" and that it was actually far more transparent than the negotiations for prior free trade agreements.

[23] The group further reiterated its claim that the secretive process is antithetical to the ideals of democracy, and is "no way to engender trust and faith in international law making with such a broad impact".

[25] In a subsequent interview with Reuters, Kirk defended the secrecy, saying he believes the USTR has conducted "the most engaged and transparent process as we possibly could", but that "some measure of discretion and confidentiality" are needed "to preserve negotiating strength and to encourage our partners to be willing to put issues on the table they may not otherwise".

[26] He dismissed the "tension" as natural and noted that when the Free Trade Area of the Americas drafts were released, negotiators were subsequently unable to reach a final agreement.