Six weeks ago, Sen. Barbara A. Mikulski announced that she would not seek re-election in 2016, signaling the end of a long and loud career in Congress. Though she slowed down a bit in recent years, Mikulski always garnered more media attention than other members of the state's congressional delegation, and certainly far more than Paul Sarbanes, the brilliant but quiet man conservatives once ridiculed as Maryland's "stealth senator."

Now, with the five-term Mikulski in retirement mode, the man who replaced Sarbanes after that long-serving senator's retirement in 2006, Ben Cardin, has quietly stepped into the national spotlight on two very different fronts — as the Obama administration's point man in the Senate on the Iran nuclear negotiations and as a provocative big-idea man on tax reform.


The indictment on corruption charges of New Jersey Sen. Robert Menendez, until recently the top-ranking Democrat on the Senate Foreign Relations Committee, thrust Cardin into that position. He stepped into a whirlwind, too, with Republicans and several Democrats embroiled in a confrontation with the White House over the deal with Iran.

Members of the Senate want some authority over any agreements reached with Iranian leaders by the U.S. and its five negotiating partners.

On April 2, President Obama announced the framework of an agreement that would keep Iran from stockpiling materials needed to make nuclear weapons in exchange for the gradual lifting of sanctions against the country.

Of course, Republicans, in keeping with efforts to deflate or destroy almost anything Obama tries to do, have been critical. Last month, while the U.S. was still in the midst of intensive negotiations over the nuclear program, 47 Republican senators sent an open letter to Iranian leaders warning that any deal with Obama must get congressional approval and could be abandoned by a future president. The letter was not only a slap at Obama, but at the ideal of a united American front in diplomatic talks toward a safer world.

"It was outrageous, it was wrong," Cardin said Monday in an interview. "It served to undermine the president, and we should never be doing that."

The author of the letter, an Iraq War veteran and freshman Republican from Arkansas named Tom Cotton, suggested in a recent interview with Jeffrey Goldberg of The Atlantic that Obama's deal with Iran would do more harm than good and maybe even lead to nuclear war down the road. A short and limited military action soon, initiated by the U.S. or Israel, might be more effective, he suggested.

Compare that kind of thinking with the approach of Cardin — a smart, level-headed, pragmatic Democrat who has been proving to be the grownup in the room since way back, during his time as speaker of the Maryland House of Delegates.

Cardin reached Congress in 1987, taking Mikulski's House seat when she ran for the Senate. A serious but affable man, he has always had a wonk's devotion to the details of budgets and deals without seeming like one. Cardin is knowledgeable and conversant on a wide range of topics, but he doesn't speak in catchy phrases or rhymes, and grandstanding is not something you associate with him.

A politician? Certainly. But some politicians are also public servants, and Marylanders have had a run of them in Sarbanes, Mikulski and Cardin.

As he steps into the Iran-nukes morass this week — 30 pounds lighter, he says, after eliminating snacks, sweets and alcoholic beverages from his diet — Cardin's skills as a negotiator will be tested. "Bridge some of the gaps that exist in Congress" is how he describes his role, in the next breath praising as "a man of integrity" the committee chairman he'll have to work closely with, Republican Bob Corker of Tennessee.

As for Israel, whose leaders oppose any deal with Iran, Cardin, who is Jewish, says: "The Israelis have a different view as to where they would like to end up. But I think we all agree that we have to keep Iran from becoming a nuclear weapon state."

While he is preoccupied with foreign affairs right now, Cardin has long been an advocate of reforming the federal tax code. Over the last few months, he's garnered significant attention — and some nice props from national opinion-makers — for proposing a federal "consumption tax" to replace the income tax for most Americans.

Cardin's proposal would impose a 10 percent consumption (or value-added) tax on all goods and services. But it would eliminate income tax on the first $100,000 in annual income for households or $50,000 for individuals. It would keep income tax for three marginal brackets, topping out at 28 percent for households above $500,000. It would keep four deductions — for charitable contributions, state and local taxes, health and retirement benefits, and mortgage interest. Cardin's proposal would set the corporate tax rate at 17 percent, about half what it is now. It would cap government spending at 10 percent of gross domestic product and give the excess revenue back to taxpayers.

It's a provocative idea — and pretty good for a junior senator.


Dan Rodricks' column appears each Tuesday, Thursday and Sunday. He is the host of "Midday" on WYPR-FM.