SPRINGFIELD, Mo. (Reuters) - U.S. President Donald Trump made his first major tax reform speech on Wednesday, but in a long list of thank yous he did not mention Gary Cohn, the White House point man on taxes who traveled with Trump to the event.

At a manufacturing company in Springfield, Missouri, Trump reiterated his longstanding call for slashing the U.S. corporate tax rate to 15 percent from 35 percent at a time when lawmakers believe they could be lucky to bring it down to 25 percent.

When asked about the omission of Cohn’s name, White House spokeswoman Sarah Sanders told reporters on Air Force One, en route to Washington from Missouri, that it was customary for Trump to recognize Cabinet members, but not advisers, in speeches.

Cohn traveled with Trump on Air Force One for the Missouri speech, in which Trump called on Democrats to join his tax overhaul effort. He said he would cut taxes and simplify the sprawling U.S. tax code for the middle class. But he offered few specifics, and tax reform will be an uphill task in Congress.

“We must reduce the tax rate on American businesses so they keep jobs in America, create jobs in America and compete for workers right here in America,” Trump said in his first presidential speech specifically on tax reform, one of his key 2016 campaign issues.

Both congressional Democrats and Republicans say tax reform is needed but the Republican goal of enacting legislation this year faces a battle in Congress, which has already failed to deliver on healthcare reform sought by Trump.

THANKS TO SOME, NOT TO COHN

During his speech, Trump did single out Cabinet members, including Treasury Secretary Steven Mnuchin, Commerce Secretary Wilbur Ross and Small Business Administration head Linda McMahon, as well as members of Congress -- more than a dozen people in all.

He asked his daughter Ivanka Trump, who is not a Cabinet member but is a staff member, to stand and be recognized in his speech at a manufacturing company in Springfield.

“Anybody I forgot?” Trump asked.

Cohn, who stood next to the stage during the speech with Sanders, has worked side-by-side for months with Mnuchin developing Trump’s tax reform strategy.

“It’s pretty standard practice for us not to specifically call out staff,” Sanders told reporters afterward. “He regularly mentions Cabinet members but very rarely mentions staff in speeches.”

Asked if the oversight of Cohn was significant, Sanders said, “Well, look, Gary is here. The president is here. They’re both working hard and extremely committed to providing tax relief for middle-class America. The president has made very clear this is a top priority for him, for his administration, and Gary is one of the people leading the charge.”

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Cohn recently criticized Trump for his comments about violence at racially charged protests in Virginia earlier this month. Trump blamed “both sides” for the violence in Charlottesville, in which white supremacists and neo-Nazis battled anti-racism protesters. Trump’s comments drew condemnation from both Republicans and Democrats.

Cohn told the Financial Times last week that the Trump administration “can and must do better in consistently and unequivocally condemning” hate groups. The former Goldman Sachs executive, who is Jewish, said he had come under “enormous pressure” to resign over Trump’s remarks.

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TAX REFORM UNLIKELY BEFORE YEAR-END

Independent analysts and lobbyists are increasingly pessimistic that Congress can act by the end of 2017, and some believe final tax legislation could be more like a straight tax cut than a reform.

“I don’t want to be disappointed by Congress. Do you understand me?” Trump said to cheers.

Trump said business tax cuts would lead to higher wages for workers by boosting economic growth and making American companies more competitive, an argument Democrats dismiss as more of the “trickle-down” economics that they blame for leaving workers behind in recent decades.

“If President Trump’s previous tax plans are any indication, the wealthy and big corporations will be the ultimate winner,” Representative Richard Neal, the top Democrat on the tax-writing House Ways and Means Committee, said in a statement.

There has been no comprehensive overhaul of the tax code since 1986.

Trump singled out Missouri’s Democratic Senator Claire McCaskill, telling voters to throw her out of office in the 2018 midterm elections if she does not get on board with tax reform.

McCaskill’s office did not respond to queries from Reuters about Trump’s remark.

After more than seven months in power, Trump and Republican leaders who control both the U.S. Senate and the House are still far from agreement on a tax package. Initially expected in the spring, tax reform legislation now may not emerge until as late as November, lobbyists say.

Trump will discuss a tax overhaul at a White House meeting next Tuesday with the “Big Six” tax reform negotiators: House Speaker Paul Ryan, Mnuchin, Cohn, Senate Republican leader Mitch McConnell and the Republican chairmen of two congressional tax committees.