It’s one of the clearest, easiest-to-understand provisions in the Constitution. And Harry Reid’s Senate flouts it routinely.

The Origination Clause in Article I, Section 7 states: “All Bills for raising Revenue shall originate in the House of Representatives; but the Senate may propose or concur with Amendments as on other Bills.” In addition to clarity, this provision has an even greater virtue: It serves a very good purpose.

The Founding Fathers required revenue measures to originate in the House because they wanted this authority to belong to the legislative body closest to the people. Plus, the Framers wanted the larger states to enjoy the most influence on matters of taxing and spending, which is the case in the House (whose seats are allocated according to population) but not the Senate (where each state gets two seats regardless of population and smaller states have outsized influence). “This power over the purse,” James Madison explained in Federalist No. 58, “may, in fact be regarded as the most complete and effectual weapon with which any constitution can arm the immediate representatives of the people.”

Senate Majority Leader Harry Reid (D., Nev.) has taken to thumbing his nose at this clear mandate. Recently, he publicly dismissed the Origination Clause as a “hyper-technical budget issue,” raised by his Republican opponents as “a fig leaf to hide their blatant obstruction.” The matter arose as Reid orchestrated a high-profile Senate floor debate on the Paying a Fair Share Act of 2012, prior to House consideration of this or any other revenue bill. Also known as the “Buffett Rule,” the Senate measure would impose a hefty new tax on millionaires.

Aware that the Republican House would no more propose new, economically debilitating taxes than Warren Buffett would voluntarily follow the rule that bears his name, Reid opted to move unilaterally. Why let a little thing like the Constitution stand in the way of making sure a red-meat, eat-the-rich proposal like this gets maximum media exposure during an election year?

It does not stop there. In its version of the legislation extending federal price controls on student loans, the Senate included a hefty tax increase — again absent the requisite House action. Then there is the Violence against Women Act, which contains a new $30 fee for immigrant visas, another Senate revenue provision that violates the Origination Clause. When House leaders uncovered this constitutional infirmity, they quickly issued a “blue slip” notification, effectively killing it.

Remarkably, as Congressional Quarterly reported, the House move “blindsided” the many constitutional illiterates in the Senate. One unnamed Senate staffer even speculated that the House’s fealty to the Constitution “may be part of some Republican plan.” This is all in keeping with how the leftist intelligentsia has viewed previous efforts to ignore the Origination Clause. The New York Times characterized one such mishap as an “arcane parliamentary mistake” the enforcement of which was designed “to block . . . everything else Mr. Reid is hoping to accomplish,” while The Washington Monthly termed it “a Democratic procedural slip-up.” As Elizabeth Price Foley, a professor at Florida International University’s School of Law and author of the excellent new intellectual history of the tea-party movement (The Tea Party: Three Principles), puts it: “Nowhere in these statements is there recognition that the holdup was constitutional rather than political.”

There is a constitutionally permissible way for the Senate to make its voice heard on revenue measures. Under widely accepted precedent, the Senate could take up House-passed tax bills, amend them, and then send the amended legislation back to the House for further consideration.

In her book, Foley lists fealty to the original meaning of the Constitution — originalism — as one of the three principles that animate the tea-party movement. Little wonder. Liberal Senate leaders, it seems, are determined to do what they want when they want to do it, Constitution or no Constitution. Even unambiguous constitutional requirements such as the Origination Clause are seen, as Foley puts it, as outdated nuisances that have no business standing in the way of today’s politically inspired “messaging” opportunities.

One of the chief operational principles of the current Senate seems to be, to paraphrase that famous line from Treasure of the Sierra Madre: “Constitution? We don’t need no stinking Constitution!” That’s one more reason why the tea-party movement remains politically relevant more than three years after its birth.

Michael G. Franc is vice president for government studies at The Heritage Foundation.