Last week, Republicans intensified their calls for the ouster of Rep. Charles Rangel from his job as chair of the House Ways and Means committee. The Harlem Democrat has been under fire thanks to a string of revelations about irregularities in his personal financial arrangements. But Nancy Pelosi is so far unmoved, with her aides telling Politico she'll wait for the results of a House ethics investigation before taking any action.

The probe has been underway for almost a year, and it's not clear when the results might be made public. So while we all wait, it's worth a quick refresher on what the ethics panel is looking at, and what it might all amount to.

The investigation is focused on several, largely unconnected examples of potential financial misconduct by Rangel. In rough order of seriousness:

• Rangel has received over $75,000 in income from a rental villa he owns in the Dominican Republic, but reportedly disclosed this income neither on his tax returns nor on Congressional disclosure forms. He has called the disclosure failures an oversight, and has paid over $10,000 in back taxes and penalties.

• Rangel reportedly worked to preserve a lucrative tax break for an oil-drilling company last year, at the same time the company's C.E.O. was pledging $1 million to a City College of New York educational center to be named in his honor. Rangel has said his work to protect the tax break was not connected to the pledge of support for the ed center.

• Rangel also reportedly used his Congressional office letterhead to solicit donors for the C.C.N.Y. educational center.

• Rangel reportedly rents four rent-stabilized apartments in the same Harlem building, at well below market rates. He reportedly uses one of them as a campaign office. City and state regulations prevent the use of rent-controlled apartments for purposes other than as a primary residence.

• Rangel and four other Democratic lawmakers took trips to the Caribbean that were funded and organized by an organization called the Carib News Foundation. These may have broken House rules on corporate-funded travel.

• In perhaps the most minor incident, Rangel's Mercedes was towed from the House parking lot last fall, after it was found that he had flouted rules barring the storage of vehicles for more than 45 days and requiring them to have license plates and a valid House parking sticker.

As wide-ranging as it is, the ethics probe doesn't encompass all the apparent irregularities in Rangel's personal finances. Last month, he filed amended disclosure forms, admitting that between 2002 and 2006, he had failed to report hundreds of thousands of dollars in income and assets, including tens of thousands of dollars in rental income from a Harlem brownstone he sold in 2004.

In assessing the seriousness of these charges, it's worth keeping in mind what Rangel's current job is. He chairs the committee that writes our tax laws. That means that, a priori, it's reasonable to hold him to a higher standard than a freshman back-bencher.

The other key issue is whether Rangel's alleged misconduct was tied, in some essential way, to his position. That is, whether he used his ability to influence policy in order to enrich himself. That's an explicit part of the allegation about preserving a tax break for a donor to his educational center -- but it's also the subtext of many of the other charges. Did Rangel's post as the nation's top tax-writing lawmaker make it easier, for instance, to take liberties with his own taxes and disclosures, or encourage him to do so?

We don't know yet -- that's what an investigation is for. But if that turns out to be the case,
that would be a serious public corruption issue. And even if investigators find that
Rangel is guilty merely of serious oversights in paying his taxes -- as he's essentially already admitted -- it might still be hard to argue that he remains the best person to be in charge of writing our tax laws.