Transcript for Trump kicks off bid to cut taxes
And we begin with the president's sweeping new tax plan, and what it could mean for middle class Americans, corporate America and the wealthiest Americans, too. Late today in Indianapolis, the president promising a revolutionary change for middle class families. But still unanswered tonight, how will he pay for it? And even some Republicans this evening saying this will be even more challenging than their efforts to kill Obamacare. ABC's chief white house correspondent Jonathan Karl, leading us off. Reporter: After failing yet again to get a Republican health care plan through congress, president trump is now promising to deliver on something even more ambitious -- a massive new tax cut. There's never been tax cuts like what we're talking about. Reporter: Details are still sketchy, but the plan calls for slashing the tax on corporations, now 35%, to 20%. For individuals and families, reducing the number of tax brackets from seven to just three. Doubling the standard deduction for families. That would mean no income tax whatsoever on the first $24,000 of income. The president insists his plan will benefit the working class, and not the wealthy. They can call me all they want. It's not going to help. I'm doing the right thing, and it's not good for me. Believe me. Reporter: Of course, it's impossible to know how any plan will affect the president because he still has not released his tax returns. But there's one big provision that would clearly benefit the wealthy. He wants to eliminate the estate tax. Something that is only paid on estates valued at more than $5.5 million for individuals, $11 million for couples. While congress will surely make changes in the plan, the president insists there's one thing he won't budge on -- that huge tax cut for corporations. 20 is my number. So, I'm not negotiating that number. 20 is a perfect number. Reporter: The president doesn't explain how to pay for these hefty tax cuts, leaving congress, already deeply divided, to figure that out. Tax reform is going to make health care look like a piece of cake. So, let's get to Jon Karl live at the white house tonight. And Jon, administration officials have said they want tax reform done by the this year. But you heard senator corker there, this is going to be a very heavy lift. Reporter: That is an extremely ambitious timeline. This will be a heavy lift even to get done by next year, David. That said, there is immense pressure on Republicans, both here at the white house and on capitol hill, to show that they can deliver on this. Jon Karl leading us off tonight. Jon, thank you.
This transcript has been automatically generated and may not be 100% accurate.