It’s the question foremost on the minds of many lawmakers: If Democrats send President Bush another war supplemental stripped of a timeline for withdrawal but including most of the $21 billion in add-ons for everything from children’s health care to agriculture disaster relief, will he still veto it?

The administration says yes. Democrats on Capitol Hill aren’t so sure.

“The president says he wants to veto spending, but of the $21 billion we’ve submitted, he’s only pointed out $75 million for spinach and $25 million for peanuts,” said one House Democratic aide, who noted both items already had been stripped from the final bill.

“He really has focused his energies on a very few things. He hasn’t complained about defense health, veterans’ health or homeland security — that’s $11 [billion] of the $21 billion. I haven’t heard him complain about SCHIP or LIHEAP or any of the other big pieces,” the aide said, referring to children’s health insurance and home energy subsidies.

But Republicans trust that the president will hold firm, and believe they can win the spin battles that would follow a second veto.

“Bush has repeatedly assured Republican leaders in Congress both in the House and the Senate that he will exercise the veto over spending,” said a House GOP leadership aide. “It really would put Democrats under a microscope in terms of their position on deficit spending, fiscal discipline and the promises they made during the campaign season. In short it would illustrate their hypocrisy on any number of levels.”

The aide also noted that Bush has to deal with Democrats on the rest of the year’s appropriations and said it wouldn’t set a good precedent if he caved on spending now.

“It certainly sets the stage for things to come,” the aide said.

Democrats, meanwhile, have probed and prodded to try to find out just what level of spending Bush would accept.

Senate Majority Whip Dick Durbin (D-Ill.) challenged Bush’s budget director, Rob Portman, on April 11 in a committee hearing, trying to pin him down on which pieces of the bill would prompt a veto.

Portman opposed the $21 billion as “excessive and extraneous,” arguing the provisions could be dealt with in regular appropriations bills or should be offset by cuts elsewhere. But Portman demurred when asked whether specific spending, such as money for Hurricane Katrina or veterans’ benefits, would prompt a veto.

“There’s about $1 billion in there for the 9/11 commission recommendations for security at chemical plants, communications systems and the like. Is this what you consider peanuts and spinach?” Durbin challenged.

Portman said much of the money already had been requested by the president — as part of his fiscal 2008 budget.

“Why should this be done as part of this emergency funding request for the war?” Portman asked.

In an interview following the hearing, Portman refused to name an overall spending level beyond which Bush would veto.

Meanwhile, Democratic appropriators haven’t yet decided for sure the shape the next supplemental bill will take. Some, including Appropriations subcommittee on Defense Chairman John Murtha (D-Pa.), want to pass a short-term spending bill that would force lawmakers and the president to come back for more war money this summer. But the greater likelihood is that lawmakers will draft a similar Iraq funding bill without a timetable for withdrawal but with as much of the add-on spending as they think they can get away with.

The add-ons for security-related spending definitely will be included, Murtha and other appropriators have said. Josh Taylor, a spokesman for Appropriations subcommittee on military construction and veterans administration Chairman Chet Edwards (D-Texas), said Edwards would push to include the $1.8 billion extra for VA health care, $1.7 billion for military construction and $3.1 billion in base realignment funding.

“There should be nothing controversial about doing the right thing for our veterans, service men and women, and their families,” Taylor said.

But some of the domestic spending could end up trimmed, depending on how eager Democrats are to call what they think may be a Bush bluff. Cutting any of the spending would be a delicate balancing act, as much of the extra spending, such as the $3.5 billion in agriculture disaster relief, the $3.5 billion for hurricane relief for the Gulf Coast, the $400 million for home energy subsidies and the $650 million for children’s health care, have backing from a number of powerful Senators and appropriators.