(Bloomberg) -- President Donald Trump warned Congress notto fumble the chance to rewrite the U.S. tax code and reinvigorate theeconomy as he kicked off his effort to sell the American public ona tax plan.

“So this is our once-in-a generation opportunity to deliver realtax reform for everyday hard-working Americans,” Trump said duringa speech Wednesday at a manufacturing plant in Springfield,Missouri. “I am fully committed to working with Congress to getthis job done, and I don’t want to be disappointed by Congress --do you understand me?”

In a speech that was light on detail, Trump put the onus onlawmakers to fulfill his call for reducing the tax burden on U.S. companies and workers.

The president has yet to sign a signature law of his own, andhis attempt to repeal much of Obamacare, his predecessor’ssignature accomplishment, ended in July with a spectacular defeatin the Senate.

Trump outlined four principles that he’s referred to before --simplifying the tax code and closing loopholes that benefit wealthyAmericans and special interests; slashing the corporate rate tocreate more jobs and higher wages; providing tax relief formiddle-class families; and cutting the tax companies would pay tobring back the trillions of dollars in profit that they currentlyhold offshore.

He repeated his endorsement for a 15 percent corporate incometax rate, down from the current 35 percent. Though some economistshave questioned whether it’s possible to achieve a rate that low,Trump stressed that workers would benefit as a result.

“We must reduce the tax rate on American businesses so they keepjobs in America, create jobs in America and compete for workersright here in America,” Trump said. “When businesses compete forlabor, your wages will go up.”

Obstructing cuts

Slashing the rate for corporations and so-called pass-throughentities to 15 percent could cost more than $2 trillion over 10years.

If tax changes are to be permanent, then any cuts have to beaccompanied by offsets such as the elimination of loopholes.

So far, White House officials and congressional leaders haven’tprovided many details about ways to offset cuts, aside fromeliminating state and local tax deductions.

The White House has said an overhaul of the tax code isessential for creating the kind of economic growth the presidenthas promised his supporters, and the speech in Missouri representsthe first step in what allies and opponents alike describe as anexceedingly ambitious legislative effort.

With regard to the corporate rate, Trump told his audience thatSenator Claire McCaskill, a Missouri Democrat who faces re-electionnext year, must support cutting it. Otherwise, “you have to voteher out of office,” he said.

While advocating for bipartisanship and support for“pro-American tax reform,” the president also called out Democratsfor “looking to obstruct tax cuts and tax reform, just like theyobstructed so many other things including administrativeappointments and health care.”

Tuesday meeting

Trump’s Treasury Secretary, Steve Mnuchin, and National EconomicCouncil director, Gary Cohn, have been meeting as part of a groupknown colloquially as the Big Six in tax talks since the spring,but have yet to propose much in the way of specifics.

Other participants are the Republican leaders of the House andSenate, Paul Ryan and Mitch McConnell, respectively, and theRepublican chairmen of the congressional tax-writing committees,Senator Orrin Hatch of Utah and Representative Kevin Brady ofTexas.

Though Cohn has been leading the administration’s tax efforts,Trump didn’t mention him during Wednesday’s speech -- even thoughhe singled out several administration officials who had accompaniedhim to Missouri.

Trump plans to meet with the Big Six at the White House onTuesday and with Democratic and Republican congressional leaders onWednesday, an administration official said.

One senior White House official said there would be ample timeto discuss the specific points of the tax plan later, but that itwas equally important to rally Americans behind the notion thatchanges would benefit the middle class.

The choice of Springfield, considered the birthplace of Route66, was intended to underscore that a tax overhaul should benefitthe Main Street America that thrived during the iconic highway’sheyday, a second White House official said.

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