Say this for Rep. Charlie Rangel, dean of the New York congressional delegation and chairman of the House Ways & Means Committee: He’s consistent.

All his various controversies involving taxes that have recently come to light? They’re actually part of a pattern that extends back over the last 30 years.

The Sunlight Foundation – a scrupulously nonpartisan organization – revealed last week that Rangel’s financial-disclosure forms from the last three decades are replete with what the foundation termed “fuzzy math.”

To wit: “Assets worth between $239,026 and $831,000 appear or disappear with no disclosure of when they were acquired, how long they were held or when they were sold.”

Specifically, Rangel’s financial-disclosure forms average about one iffy entry per year – 28 instances in 30 years of filings where Rangel failed to report either acquiring, owning or disposing of assets.

Of course, the average must be even higher – because those figures don’t reflect reports in the past year that Rangel failed to disclose:

* The existence of a rental villa in the Dominican Republic.

* His illegally stored car in the House garage.

* His four rent-stabilized apartments in Harlem, including one used as a campaign office in violation of the law.

These omissions – plus such serious issues as an apparent pay-to-play scheme to raise money for a CCNY school of public service in his name – are part of an ongoing House Ethics Committee probe.

Or, to be exact, they would be part of that probe – if the ethics committee weren’t dormant right now.

In the meantime, the ethically compromised, “fuzzy math” chairman of one of the most powerful panels in Congress just continues along, merrily drafting the nation’s tax policies.

As noted above, failure to pay taxes has already cost President Obama his first choice for secretary of health and human services and his government-performance watchdog. (It nearly – and probably should have – cost him his treasury secretary, too.)

Meanwhile, the blithe we’ll-get-around-to-it-when-when-we-get-around-to-it attitude displayed by Nancy Pelosi’s House of Representatives can’t stand.

The president should direct the Justice Department to launch a formal investigation into Chairman Rangel’s finances.

Otherwise, the public will judge – quite correctly – that there is one set of rules for the Washington elite, and another for everybody else.