The group found general agreement on a key point. Over the past three years, federal revenue has been lower as a share of the economy than at any time since 1950. Diane Lim Rogers, a “deficit hawk” from the Concord Coalition, hammered on the idea that putting the government on a sound fiscal footing will require more revenue. The others agreed. That was true even of Douglas Holtz-Eakin, who heads the conservative think tank American Action Forum and advised John McCain’s presidential campaign.