By Sam Goldfarb, CQ Staff

With large portions of the tax code set to expire at the end of the year, lawmakers are aiming to get a mandate from voters to pursue their preferred tax policies, while taking some small, practical steps to prepare for a legislative showdown that is sure to occur after the election.

This week, Democrats will get the first shot at influencing the political debate with a procedural vote on legislation that adheres to President Obama’s “Buffett Rule” by establishing a new alternative minimum tax for millionaires. Democrats have argued that wealthy taxpayers such as the billionaire investor Warren E. Buffett should not be able to pay a lower effective tax rate than people with more modest incomes.

In an attempt to realize that goal, the Senate on Monday will vote on a motion to proceed to legislation (S 2230) that would raise taxes on many households that earn more than $1 million annually and impose a minimum 30 percent tax on households that earn more than $2 million.

While Democrats are betting that voters will embrace their message of “tax fairness,” Republicans are trying to reinforce their brand as the party that keeps taxes low for every segment of society. To that end, the Republican House will vote April 19 on legislation (HR 9) that would provide a 20 percent tax deduction to businesses with fewer than 500 employees.

Neither of the tax bills that will be debated this week are likely to become law anytime soon. Opposed to any sort of tax increase, Senate Republicans are expected to block further consideration of the Buffett Rule bill. Arguing that it would be a windfall for wealthy lawyers, entertainers and financial managers, Democrats have similarly vowed to halt the progress of the small-business tax cut once it is sent to the Senate.

Both bills, however, are meant to help lawmakers as they campaign for re-election and provide momentum to causes that could potentially be settled later this year, when Congress will confront the expiration of sweeping tax cuts (PL 107-16, PL 108-27) that were enacted last decade and temporarily extended at the end of 2010.

“We hope to pick up some Republicans when the Senate votes on April 16,” the Senate’s No. 3 Democrat, Charles E. Schumer of New York, told reporters on April 5. “But if we come up short, even if we come up short of the 60 votes needed, we’re going to keep pushing this issue all year long.”

Noting that a majority of Americans appear to support some version of the Buffett Rule, Schumer predicted that Republicans would start to modify their opposition to the tax “and move more quickly than people think.”

Republicans argue that the Buffett Rule will be a losing proposition for Democrats because it does not address voter concerns about the economy. They also point out that it would make only a small dent in the federal budget deficit, with the Joint Committee on Taxation (JCT) estimating that the Senate bill would raise $46.7 billion over 10 years when compared with current law.

Shifting from defense to offense, Republicans are trying to put Democrats in the awkward position of rejecting a tax cut for smaller enterprises. Republicans say the one-year tax break would lead companies to hire more workers. But Democrats argue that there are better ways to encourage hiring and note that the tax cut would add nearly $46 billion to the deficit, according to the JCT.

Making Preparations

Even as they jockey for political position, lawmakers know that they also face logistical challenges.

Absent congressional action by the end of the year, reduced rates enacted as long ago as 2001 will expire for every person who pays income or Social Security taxes. In addition, Congress is under pressure to retroactively extend a host of already expired provisions, including a “patch” for the alternative minimum tax to prevent a large increase on thousands of middle- and upper middle-income taxpayers.