One of the most influential Oregonians ever to be elected to Congress, along with Senator Wayne Morse, Ullman presided over the powerful House Committee on Ways and Means during a period of time in which he was deeply involved in shaping national policy on issues relating to taxation, budget reform, federal entitlement programs, international trade, and energy.

After teaching American history and government at Port Angeles High School in Washington for two years, Ullman earned a master's degree in public law from Columbia University in 1939.

For example, as The New York Times noted, "Among Mr. Ullman's most important actions as committee chairman was his sponsorship of sweeping legislation to cut taxes in an effort to help shore up the United States economy.

His bill, which gave more than $20 billion in income tax rebates to Americans in the spring of 1975, brought the Oregon Democrat national recognition after almost two decades of relatively quiet Congressional service."

On many regional issues, Ullman was a de facto leader of the Pacific Northwest's Congressional delegation, along with Senator Henry "Scoop" Jackson (D-Wash.) and congressman (later to be House Speaker) Tom Foley (D-Wash.).

In addition, Ullman was well known for his longstanding advocacy on behalf of American Indian tribes in Eastern Oregon, which he felt had historically been treated unjustly by the federal government with respect to treaty, land and other issues.

Ullman's electoral defeat was widely attributed to the nationally prevalent anti-incumbent and anti-government mindset; the presence in his House race of an independent candidate; the increasing conservatism of the Second District; to his advocacy for a value-added tax similar to that now used in the European Union and other nations as a partial alternative to what he viewed as inequities in the existing Federal income tax system; and to the decision of President Jimmy Carter to concede defeat in the 1980 presidential election before the polls in Oregon were closed, an act which Ullman and others believed discouraged many people from voting.