On Wednesday, Lois Lerner, the IRS official overseeing the tax-exempt organizations office, refused to testify during a hearing on Capitol Hill, and was attacked by some Republicans on the House committee. Her brief appearance was the beginning of a five-hour session marked by angry outbursts and allegations of political motives.

The Treasury Department's inspector general, who faulted the IRS for flagging conservative groups for extra scrutiny, is now investigating how the agency is monitoring the political activities of tax-exempt groups. These so-called social welfare organizations are not supposed to be primarily about politics, although many seem to be.

One commissioner ran the IRS when it engaged in targeted scrutiny of conservative groups applying for tax-exempt status. A second commissioner was in charge when the agency continued to withhold information from Congress. On Tuesday, they testified together for the first time, to the Senate Finance Committee.

NPR's Peter Overby reports on the Congressional testimony of IRS officials in response to the scandal over special scrutiny of tea party groups. Underneath all the politics, there's a policy question that hasn't been addressed.

The House Ways and Means Committee became the first oversight panel in Congress to weigh in on the IRS tax-exempt group controversy on Friday morning.

The Justice Department is investigating the IRS's flagging of grass-roots conservative groups that sought nonprofit status. But some lawmakers want the debate extended to look at the well-financed activities of existing 501(c)(4) groups that spent millions in the 2012 elections.

The IRS is under fire for directing additional scrutiny toward conservative groups seeking 501(c)(4) status. But the controversy reveals a question with no clear answer: Precisely what are so-called social welfare organizations allowed to do in electoral politics?

The Securities and Exchange Commission is conducting an investigation in the hottest sector of Washington's influence industry: political intelligence. It's the business of collecting highly detailed information from Congress and the regulatory agencies, and using it to make money on Wall Street.

On Friday, the IRS officer in charge of tax-exempt groups apologized for the agency's use of the terms "tea party" and "patriot" on paperwork as a reason for giving applicants additional scrutiny. Conservative groups say the admission validates their complaints from last year that they were being singled out by the Obama administration.

Reversing a trend that dates back to the 1990s, the lobbying industry is becoming more secretive. And campaign money now looms ever larger as a critical element in the persuasion business.

Federal election law gives married couples some advantages in making political contributions. The Federal Election Commission this week tried to make those same breaks available to couples in same-sex marriages — but commissioners said they're thwarted by the federal Defense of Marriage Act.

The Boston bombing probe might have been helped if the explosives were marked with microscopic identifiers called taggants. But the technology has long been off-limits, thanks to the National Rifle Association and its industry allies.

Sens. Lisa Murkowski and Ron Wyden have sponsored a bill aimed at outing the wealthy donors, corporations and unions that financed some $300 million in secretly funded campaign ads last year. Initial reactions showed what the two senators are up against.

Bob Perry became a billionaire putting up houses in Texas. He spent millions of his wealth helping Republicans and pioneering new ways to inject big money into politics. Perry died Saturday at the age of 80.

Nearly 500,000 people have petitioned the Securities and Exchange Commission to make publicly-traded corporations disclose their political spending. The question is: How much clout do 500,000 people actually have?

Senators on a Judiciary subcommittee on Tuesday heard about the hundreds of millions of dollars spent in political campaigns last year from secret donors, and why federal agencies are nearly powerless to do anything about it.

Ever since the tragedy in Newtown, Conn., in December, the National Rifle Association has promised a plan for keeping schoolchildren safe.

In a step toward fuller disclosure, the agency is asking more questions of the entities whose multimillion-dollar ad budgets helped clog the airwaves during election season.

The online government database was supposed to bring some transparency to the multimillion-dollar market in political TV ads, letting the public more easily see how much politicians and advocacy groups spend in major markets. But it also has inadvertently opened up some of those involved to fraud.

One argument used by conservatives in the Supreme Court cases is that gay Americans have become so politically powerful that they don't need special attention from the courts. Whether or not that's true, NPR's Peter Overby reports, it's clear that advocacy groups for the lesbian, gay, bisexual and transgendered community have built a strong network of lobbyists and political activists in Washington.