He unsuccessfully challenged two-term incumbent Blanche Lincoln for the Democratic nomination for the U.S. Senate, losing in the June 8, 2010, runoff after neither won a majority in the May primary.

Upon graduation from Stanford, he won a Rhodes Scholarship to Oxford University in England, where he received a Master of Philosophy degree in economics in 1986.

Following the election of fellow Arkansan Bill Clinton as President of the United States, Halter joined the new administration as a senior adviser in the Office of Management and Budget (OMB) in 1993.

He also coordinated the work of the President's Management Council, a group consisting of the Chief Operating Officers of the Federal Cabinet departments.

[citation needed] On October 1, 1999, Halter was nominated by President Clinton to serve as Deputy Commissioner of the Social Security Administration.

[11] On March 1, 2010, Halter announced his candidacy in the 2010 U.S. Senate election, challenging two-term incumbent Blanche Lincoln in the Democratic primary.

[15] Halter supports investment in clean energy, making broadband accessible to all Arkansans and raising the minimum wage.

He criticized Blanche Lincoln for watering down the act, claiming she "sided with the insurance companies and HMOs who gave her campaign more than $800,000.

He supports reforms that get banks lending money to Main Street and small businesses whilst preventing a repeat of the financial crisis.

Halter supports the creation of an independent watchdog agency, an end to sky-high corporate compensation, and better checks and balances on financial industry practices.