The federal deficit hit $311 billion for the first half of fiscal year 2008, up from $162 billion the year before.
Republicans and Democrats want to add measures that could lead to a Bush veto.
Bush's budget request Monday cut funding for renewable energy, but increased spending for science.
His $3.1 trillion budget would be the largest ever.
Rising entitlement costs and Iraq war expenses take a back seat to shorter-term stimulus plans.
Jim Nussle strikes a note of caution on government finances as the economy potentially slows down.