Senate Republicans used test votes Thursday to prove they can derail a defense bill that contains a Democratic-written, $35 billion anti-terrorism plan that President Bush and GOP lawmakers call too expensive.

The two near-party-line votes signaled that the Senate's majority Democrats don't have the 60 votes they would need to overcome GOP procedural obstacles and muscle their anti-terror package through the 100-seat chamber.

That means that at some point, negotiations between the parties are likely on how much should be spent to respond to the Sept. 11 attacks. Bush has promised to veto anything surpassing $20 billion, although he has said he will seek more money next year.

"Anyone who was living in this country on Sept. 11 knows deep in their heart of hearts that we had better start to do something now," said Sen. Robert Byrd, D-W.Va., chief author of the Democratic plan.

But Republicans said billions in emergency funds already are flowing.

"There is no necessity for additional money now," said Sen. Ted Stevens, R-Alaska, who led the GOP effort to cut the Democratic package.

Stevens also prepared an amendment, which he billed as a compromise, that contained the same $20 billion Bush wants to spend, but more than the president sought for New York, bioterrorism and food safety. Its wide-ranging cuts in the Democrats' larger package include defense, federal law enforcement and border security.

With a vote possible Friday on their alternative, Republicans and White House officials were hunting for support from moderate Democrats in hopes of dealing an embarrassing setback to Senate Majority Leader Tom Daschle, D-S.D., and his party.

In the two 50-48 test votes -- seven votes more than the 41 they needed -- Republicans stripped bill language declaring the Democrats' extra $15 billion to be an emergency. Sen. Russell Feingold, D-Wis., was the only senator who crossed party lines.

That emergency declaration would have let the Democratic bill exceed budget caps. Having erased it, Republicans prepared for another procedural vote declaring the entire bill a budget buster and thus derail it.

Each side used Thursday's debate to score partisan points in a battle that struck themes that could resonate in next year's congressional elections.

Echoing criticisms they aimed at Bush's father a decade ago, Democrats praised the president's handling of the war overseas but said he was not adequately trying to enhance Americans' security at home.

"Come back home, Mr. President. We need your same vigorous action on homeland security," Sen. Barbara Mikulski, D-Md., said at a news conference as Senate debate began.

Like the current president, the elder President Bush's popularity soared during a war, in his case in the Persian Gulf area. He lost his 1992 re-election bid after Democrats repeatedly charged him with ignoring the weak economy at home, just as they consider domestic issues to be this president's Achilles heel.

Republicans have accused Democrats of needlessly delaying the $318 billion defense bill during wartime by attaching the anti-terror spending to it, knowing a veto was promised. They also say Democrats are trying to outbid the GOP for voters' support.

The Democratic plan would boost spending beyond Bush's proposals for local law enforcement, labs at federal and local facilities, the Postal Service, airport security and aid to New York and other states where terrorists struck.

Three days after hijacked airliners destroyed the World Trade Center and damaged the Pentagon, Congress approved $40 billion to fight terrorists.

Bush was given control of half, while lawmakers must vote anew on the details of the second $20 billion. Republicans say there was agreement to limit the spending to $40 billion, while Democrats say that was just a starting point.

In a letter to congressional leaders that renewed Bush's veto threat, administration officials said that through November, only $6 billion of the $40 billion has been spent.

"Many of the costs associated with the response to and recovery from the attacks will not be known for many months and therefore, the agencies will be unable to target additional funds to these needs," the White House wrote.

The GOP-led House approved a $20 billion package last week after blocking Democratic efforts to add billions to it.