The grades are in, and you can see how lawmakers fare on the most important issue of our time: the grand divide between America's rich and everybody else.

Lots of Americans today are watching how members of Congress go about their business. Environmentalists and electrical workers alike keep track of key congressional votes. So do retailers and farmers. Even poker players are following how members of Congress rate on the issues that hit home.

All these groups have, of course, their own specific priorities. Their representatives are looking out for their own supporters, not looking at the “big picture.”

That big picture, meanwhile, hasn’t been particularly pretty for some time now. The vast majority of Americans — the 99 percent — have been racing on a treadmill ever since the 1970s. We’re working harder, with little to show for our effort. But for our top one percent, it’s an entirely different story. They’ve been doing just fabulously.

The growing gap between the rich and the rest of us didn’t just happen by chance. Conscious political decisions — on taxes, on trade policy, on regulations — have all been driving the divide.

Who made these decisions and changed the rules that determine how the U.S. economy operates? Ultimately, that responsibility rests with Congress. So shouldn’t we be rating our lawmakers on their law making?

My colleagues and I at the Institute for Policy Studies think so. We’ve just assembled the first congressional report card that grades lawmakers on what they’ve done to make sure that all Americans, not just a privileged few, can share in the wealth that we all create.

This new report card compares members of Congress on 40 legislative actions taken over the last two years that either improve opportunities for our 99 percent or feather the nest of America’s most affluent one percent.

Up for review: everything from legislation to establish a “Buffett Rule” minimum tax that all wealthy Americans must pay to a bill that would raise the minimum wage and index it to inflation.

Lawmakers received a positive point for taking an action that narrows America’s economic divide and a negative point for attempts to widen it. The report card, now available online from the Institute for Policy Studies, totals these points and then translates the numbers into overall letter grades.

Some lawmakers, after all this tallying, look really good. Five senators — Sherrod Brown of Ohio, Dick Durbin of Illinois, Al Franken of Minnesota, Bernie Sanders of Vermont, and Sheldon Whitehouse of Rhode Island — all rate an “A+,” as do 14 members of the House of Representatives.

But 48 members of the House end up with an “F,” and 11 Senators similarly flunk. All of these lawmakers — a list topped by Kevin Brady, the Texas representative with the single most one percent-friendly grade point average in the entire Congress — have failed 99 percent of their country.

These lawmakers, naturally, don’t see things that way. They consider their votes to enrich the rich in everyone’s best interest. The less the one percent pays in taxes, their argument goes, the more they will invest in and grow the economy.

Americans hear this claim all the time. Now the nonpartisan research arm of Congress has put that claim to the test.

A new Congressional Research Service report examines whether any link exists between economic growth and tax rates on the rich. This report crunches data since 1945, years that have seen the top tax rate on America’s rich drop from over 90 percent to 35 percent today.

What has this steep decline in tax rates on high incomes generated? In terms of savings, investment, and productivity growth: nothing. The Congressional Research Service has found no correlation between lower taxes on higher incomes and economic growth.

“The top tax rates,” concludes the CRS, “appear to have little or no relation to the size of the economic pie.”

But tax rates on the rich do significantly impact how that pie gets sliced. The slice that went to the nation’s top 0.1 percent back in 1945 amounted to 4.2 percent of America’s national income. By 2007, that slice had tripled in size to 12.3 percent.

Members of Congress are still slicing away today. The difference? We now have a report card that grades their slicing.