WASHINGTON — Yes, if Mitt Romney wins the White House and his Republican allies retake the Senate, he could shred most of President Barack Obama’s health care law without having to overpower a Democratic filibuster.

But it won’t be as easy as some Republicans portend, and it certainly won’t be quick.

Why?

Because any realistic effort to repeal the Affordable Care Act – as opposed to last week’s quixotic vote in the GOP-controlled House – is sure to get jumbled together with lots of other issues, including Medicare, taxes, food stamps and defense spending.

And that’s because Republicans have to first pass a budget. It’s the only way they can invoke special Senate rules that allow legislation to pass with just a simple majority vote – instead of the 60 votes needed in the 100-member Senate to beat a filibuster.

Passing a budget requires answering a raft of questions unrelated to the relatively simple idea of repealing “Obamacare.” How much to cut the deficit? Should Medicare be overhauled and Medicaid bear sharp cuts? Is it realistic to sharply boost defense programs, as Romney would like, in such an atmosphere?

The first step is to pass a budget resolution – a nonbinding, broad-brush outline of budget goals like cutting or increasing taxes, or slowing increases in Medicare. A budget resolution sets the terms for follow-up legislation that’s called a reconciliation bill in Washington argot.

Two years ago, Democrats used a reconciliation bill to finalize the health care law with a 56-43, party-line vote in the Senate.

Republicans have a problem in that there’s a lot more on their agenda than just repealing the health care law, and it’s all going to have to be crammed into a budget resolution and follow-up reconciliation bill, too.

“They’re going to want to use that budget resolution to set up a tax bill, they’re going to want to do other deficit reduction,” said Hazen Marshall, a GOP lobbyist and the Senate Budget Committee’s top aide in 2001 and 2003 when reconciliation bills were used to push former President George W. Bush’s tax cuts through Congress.

“So I would think it’s just going to take some time to get everybody on the same page as to what the budget resolution’s going to look like,” Marshall said.

In 2001, when Republicans set about the relatively simple task of cutting taxes in an era of unprecedented budget surpluses, it took them until Memorial Day to pass the legislation.

What Republicans would confront next year is far more difficult – wrenching cuts to programs popular with voters. A more apt comparison might be the GOP’s budget efforts of 1995, when it took the party until November to complete action on its budget plan.

“It’s not that it’s not doable. It absolutely is doable,” said a senior House GOP budget aide. “It’s just going to take a lot longer than everybody wants it to. And people aren’t anticipating the pain of each step to get to that point.” The aide spoke on condition of anonymity because he wasn’t authorized to speak on the record.

Republicans currently hold 47 Senate seats. If they take control of the Senate, it’s not likely to be by more than 1 to 4 votes, well short of 60. That would put lots of leverage in the hands of Senate GOP moderates like Susan Collins of Maine and Scott Brown of Massachusetts, should he win his difficult re-election bid.

Both Collins and Brown cast votes earlier this year against the House GOP budget plan, authored by Rep. Paul Ryan, R-Wis. At the center of Ryan’s plan was controversial overhaul of Medicare that would transform it into a voucher-like program for those who retire in 10 years. Also voting against Ryan’s plan was Rep. Denny Rehberg, R-Mont., who Republicans are counting on to win a Senate seat this fall as a building block to a GOP majority.

Keith Hennessey, a former GOP Senate and White House official, says that if Republicans follow past practice, they’ll try to forge a center-right agreement that includes spending cuts but no tax increases. But he noted that the willingness of some Republicans to embrace tax increases could complicate matters.

“You look at the Republicans and you see that there’s going to be a spectrum on how deep they’re going to be willing to cut various things,” said Hennessey, currently a research fellow at the Hoover Institution at Stanford University. “The question is just how far toward the Ryan plan can you get the moderate Republicans.”

On the other hand, combining the repeal of Obama’s health care law with other GOP priorities like curbing the deficit gives lawmakers who are not part of the leadership plenty of incentive to vote for the package.

“When elections are about certain policies and are defined on that, you’ve got momentum to do those things,” said House GOP Whip Kevin McCarthy of California.

A simple-majority reconciliation bill could certainly cover the health care law’s tax increases – including the penalties used to enforce the individual mandate to buy insurance – and subsidies for insurance premiums.

Republicans, however, could not use the filibuster-proof budget process to repeal provisions in the health care that don’t have a direct impact on the government’s balance sheet. For example, it still would likely take 60 Senate votes to repeal the law’s requirement that insurance companies cover people with pre-existing conditions.

Experts say leaving the insurance reforms intact on their own is economically unsustainable because the ratio of sick to healthy people in the plans would be out of balance.

“If you were to remove everything else in reconciliation and be left with the insurance provisions, you have something that everybody recognizes is unworkable,” said former Congressional Budget Office Director Douglas Holtz-Eakin. “I think if you take enough out, the rest probably has to go.”