GOP leaders in the House and Senate are waxing optimistic about their ability to complete a slew of high-profile and contentious bills before Congress adjourns for the August recess in just four days.

In fact, a number of measures that have befuddled lawmakers for months are finally within reach of passage in one or both chambers, including conference reports on energy policy and highway funding, a Central American trade pact, a bill to protect gun manufacturers from lawsuits and emergency funding for veterans’ health care.[IMGCAP(1)]

But plenty of other measures will likely have to wait until September before they see action again — notably a Defense Department authorization bill and nine of the 11 annual spending bills.

In the Senate, Democratic leaders were in a strategic quandary Monday as they tried to figure out what to do about dueling motions to limit debate on both the Defense bill and the gun manufacturers liability measure. Motions to limit debate, or cloture, require 60 votes to pass.

On the one hand, Democrats have excoriated Senate Majority Leader Bill Frist (R-Tenn.) for what they see as a premature end to the Defense debate during a time of war. Democrats argue that it’s rare for a majority leader to file for cloture on the mammoth Defense authorization bill after only two and a half days of debate. The last time something similar happened, in 1997, cloture was rejected in favor of more debate, noted a Democratic aide.

On the other hand, Senate Minority Leader Harry Reid (D-Nev.), along with at least nine other Democrats, supports the gunmakers’ liability bill. Reid called a caucus meeting Monday evening to gauge how the rest of his colleagues wanted to vote on the two measures.

Democrats emerged from that meeting still undecided as to whether to band together to protest cutting off debate on the Defense bill. Senate Minority Whip Dick Durbin (D-Ill.) said that if all Republicans vote for cloture, which is far from a sure thing, the Senate may indeed move to limit debate on the measure.

“It’s going to be very close,” said Durbin. “I don’t know that there’ll be a Caucus position on it.”

Regardless of the vote on Defense, Democrats are set to split on any gun manufacturers’ liability bill to give Republicans more than the 60 votes they need to its begin consideration, either today or Wednesday.

Senate Armed Services Chairman John Warner (R-Va.) may not even get the support of all 55 Republicans on today’s cloture vote, since many had planned on lengthy debates over proposed military base closings in their states. For example, Sen. John Thune (R-S.D.) said he may not vote to invoke cloture because he wants “more time” to debate his amendment opposing the closing of Ellsworth Air Force Base in his state.

Assuming the gun liability bill becomes the topic du jour, the measure’s odds of passing this year have improved tremendously since the previous Congress. On Monday, Sen. Larry Craig (R-Idaho), the bill’s lead sponsor, signed up a 60th co-sponsor, Sen. Robert Byrd (D-W.Va.), said Craig spokesman Dan Whiting.

Plus, Republican gains in the 2004 elections make it less likely that gun control advocates, such as Sens. Dianne Feinstein (D-Calif.) and Jack Reed (D-R.I.), will be able to attach amendments banning .50 caliber rifles, or closing the so-called gun show loophole on gun-owner background checks.

“We believe there’s been enough a shift in the last election to make the difference” between adoption and defeat of those amendments, said Whiting. Last year, when Republicans held only 51 seats, the Senate narrowly adopted several gun control amendments to the gun manufacturers liability bill.

In the House, Republican leaders were furiously trying to round up enough votes for the Dominican Republic and Central America Free Trade Agreement, which is expected to get a vote on the House floor Wednesday or Thursday.

Indeed, reports of deals and talks with Members concerned about the trade agreement’s impact on the textile industry in their states, or with those wanting to open up more trade with communist Cuba, abounded on Monday. Others suggested that leaders were trying to dangle lucrative highway projects in front of wavering Republicans as an enticement to vote for DR-CAFTA. In fact, the timing of a potential conference report on a nearly $300 billion highway funding could be affected by the vote.

Meanwhile, House and Senate negotiators were trying to complete an energy policy conference report as of press time Monday.

Over the weekend, House Energy and Commerce Chairman Joe Barton (R-Texas) had to face the reality that Senate conferees would not accept his proposed compromise to give the makers of the gasoline additive methyl tertiary butyl ether, or MTBE, immunity from some lawsuits.

While Barton got the support of Rep. Charlie Bass (R-N.H.) for an $11.4 billion fund to clean up MTBE groundwater contamination, particularly in the Northeast, Sen. Judd Gregg (R-N.H.), along with many Democrats and other Northeastern Republicans, rejected the proposal — dooming its chance of being included in the conference report.

With MTBE essentially off-the-table, negotiators aimed to put the final touches on the conference report last night, with hopes of having a House vote on it as early as Wednesday and a Senate vote by Thursday, according to aides.

While success on the energy bill seems imminent, the same does not appear to be true for Congress’ ability to avoid a catchall omnibus spending bill by Oct. 1 — the start of the government’s new fiscal year and the statutory deadline for appropriations to be enacted.

Indeed, only two spending measures will likely make it to the president’s desk by the end of the week: The Interior appropriations bill, which will likely include $1.5 billion in emergency veterans health care spending, and the legislative branch spending bill that funds Congress itself.

Appropriators had hoped to be able to finish work on the homeland security appropriations bill by the end of the week, but Homeland Security Secretary Michael Chertoff’s announcement two weeks ago that he would restructure his department has put a kink in those plans.

Only two other Senate appropriations bills — Energy and Water, and State and Foreign Operations — are even ready to be reconciled with their House counterparts. While the House passed all 11 of its spending bills before July Fourth, the Senate has only passed five of its 12 measures. The Senate Appropriations Committee has passed a total of 11 appropriations bills, but Frist has not scheduled debate time for the seven awaiting floor votes before the August break.

Committee action on the Senate’s Defense Department appropriations bill has been postponed several times.