WASHINGTON (AP) — Promoting farm subsidies was once a no-brainer for rural members of Congress seeking re-election. This year, it's a bit trickier.

As lawmakers wade cautiously into writing the next five-year farm bill, agribusiness and farmers' lobbyists are preparing for the worst. With little appetite for spending on Capitol Hill, subsidy cuts in the billions of dollars are on the table as rural voters also cry out for less government.

It doesn't help that farm business is booming.

"What's different this time is we have very strong commodity prices," says Roger Johnson, president of the National Farmers Union. "And that is generally not a really good time to write a farm bill because everyone who is projecting the future says, 'Oh, this is going to last forever.'"

Farm bills in 2002 and 2008 also were driven by rural election-year politics. Lawmakers, particularly in the Senate, curried favor with farm interests in their states by slipping their priorities into the bills. Taking care of everyone's needs ensured passage and subsidies remained almost untouched.

But this year, many of farmers' traditional allies are just as concerned, if not more concerned, about voters' calls for less spending.

Sen. Pat Roberts, senior Republican on the Senate Agriculture Committee and a veteran of many farm bills, says his constituents aren't asking about farm subsidies as much as they used to. He says he gets more questions about government regulations that farmers see as burdensome. Traditional farm issues and the impact of farm policy have gotten somewhat lost.

"I don't think most people who run for office realize there is still a significant farm vote," he says.

Nowhere was that more clear than in Iowa, where presidential candidates have wooed farm country for decades. Several of the contenders in the Iowa caucuses actually spoke out against corn-based ethanol, a position unthinkable in the past.

Farm-state members have already said they will support eliminating some subsidies. Last fall, the heads of the House and Senate agriculture committees — Republican Rep. Frank Lucas of Oklahoma and Democratic Sen. Debbie Stabenow of Michigan — negotiated a farm bill that cut $23 billion from agriculture and nutrition programs, hoping to piggyback it on the budget-cutting supercommittee's bill. When the supercommittee fizzled, so did their hopes for a speedy farm bill.

This year, they are starting over with more input from other agriculture committee members. But direct payments, a type of subsidy paid without regard to crop price or crop yield and costing taxpayers about $5 billion a year, are still a top target as the Senate Agriculture Committee opens hearings on the legislation Wednesday. That was cemented by President Barack Obama's call to eliminate them in his budget proposal Monday, which put forth a $32 billion cut in farm programs.

That's a strong contrast from 2008, when Obama supported the last farm bill while he was campaigning for president. That legislation was far more generous — even raising some subsidies — than the bill Congress is weighing this year.

Former President George W. Bush also played both sides. He signed a robust farm bill before the 2002 midterm election year but later called for cuts. In 2008, when he wasn't up for re-election, he vetoed the next farm bill. Republicans up for re-election in the House and Senate joined Democrats in overriding the veto.

Since then, farm country has seen much of that GOP support fade away. Farm-state Democrats were largely swept out of Congress in the 2010 midterm elections, and several Republicans who eventually filled their seats on the House Agriculture Committee are more affiliated with the anti-spending tea party than they are with farm interests.

Unclear is how aggressively those conservatives will support farm subsidies — and, if they do, whether they will be able to persuade party leaders and other congressional conservatives to go along. House opposition is seen as the biggest obstacle to getting a farm bill done this year.

Rep. Tim Huelskamp, R-Kan., one of the tea party conservatives on the agriculture panel, says he is telling constituents that direct payments will have to go. "Some folks say we want you to defend it to the end of the day, and I say that's not what's going to happen."

Huelskamp believes there should still be some sort of safety net for farmers when prices drop or crops are destroyed. But he says frustration over government regulation — labor and environmental laws in particular — is the top issue on farm voters' minds. People understand they will have to take a cut, he says.

No one envisions a farm bill that eliminates subsidies entirely. The compromise Stabenow and Lucas reached last year would have cut spending while creating a whole new subsidy to protect farmers when their revenue drops.

"There are a lot of land mines and we just have to see how it plays out," says Minnesota Rep. Collin Peterson, the top Democrat on the House Agriculture Committee. He warns that Congress shouldn't get too confident about cutting farm programs.

If the agriculture economy crashes, he says, "there isn't going to be any money to bail anybody out."