The president has a habit of exaggerating; this time his exaggeration is the size of his proposed tax cut. (Meg Kelly/The Washington Post)

As Republicans in Congress work to finalize a major tax cut bill, the centerpiece of President Trump's “MAGA-nomics” plan, Americans are not entirely enthusiastic about it. In the Wall Street Journal/NBC News poll released this week, 25 percent said the bill is “good idea,” a potential pitfall as Trump and GOP lawmakers try to sell tax cuts for corporations and individuals to the nation Thursday.

Trump has repeatedly tried to generate excitement for tax cuts by giving speeches in Indiana and Pennsylvania and tweeting often about “massive tax cuts” that “you deserve.” Yet, support for the bill doesn't seem to be improving.

A Washington Post-ABC News poll in September asked, “Do you support or oppose Trump’s tax plan?” Twenty-eight percent said they “strongly” or “somewhat” supported the plan, almost exactly what the WSJ/NBC poll conducted last week showed. In that poll, what support there was came largely from Republicans; 54 said the tax plan is a "good idea," while 22 percent of independents and 4 percent of Democrats thought so.

What's clear from numerous polls in recent weeks and months is that Americans across the political spectrum don't think the wealthy or big businesses should get a tax cut. And few see taxes as the top issue Congress should tackle.

The latest Politico/Morning Consult poll out Wednesday showed the highest support for the tax bill overall: Forty-eight percent said they "support" or "somewhat support" it. But sentiment dropped sharply when people were asked specifically about a tax cut for big business, a key part of Trump's plan. Thirty-nine percent thought "large corporations" should pay less in taxes.

The lukewarm support for Trump's tax cuts is a contrast to the sentiment President Ronald Reagan faced heading into the 1986 tax overhaul, which Trump is trying to emulate. According to a Gallup/Newsweek poll in August 1985, 46 percent of Americans thought Reagan's proposal to change the federal tax system was a "good idea." Reagan also enjoyed substantially higher approval ratings of his presidency than Trump does. Reagan's approval rating was 60 percent in 1985, giving him a solid base of support as the House introduced the tax reform bill in December of that year.

“Without President Reagan's support, the 1986 Act never would have happened,” says Pete Davis, president of Davis Capital Investment Ideas, who worked for many years on the Joint Committee on Taxation in Congress. “The bill almost died at least a dozen times.”

Trump's approval rating is below 40 percent, which might be a challenge as he plays the role of salesman on taxes.

The centerpiece of Trump's tax plan is a substantial cut for corporations, which is particularly unpopular with the public. Republican lawmakers and some Democrats say the United States needs to lower its business tax rates to make American companies competitive with foreign rivals. The GOP bill would reduce the top rate from 35 percent to 20 percent.

But polling indicates that most Americans think taxes should go up for large corporations and the wealthy. A CBS poll released Wednesday found 80 percent think that taxes for big business should stay the same or go up. This echoes a Washington Post-ABC poll in September, which found that 73 percent of Americans believe that the current tax system favors the wealthy and 65 percent believe businesses pay too little.

Trump and Republican leaders in Congress have been trying to cast the corporate rate cut as a way to create more jobs and higher wages for workers, since good-paying jobs remain a concern for many Americans.

“We will cut taxes on American businesses to restore our competitive edge and create more jobs and higher wages for American workers,” Trump said at a speech in Indianapolis in late September.

But polls indicate that Trump and Republicans have a lot more work to do to sell the tax bill to the public. In the CBS poll conduced last week, 56 percent said Trump's plan will benefit the rich; 13 percent said it would benefit the middle class.

Some question whether there is appetite at all for a tax cut. A Bloomberg poll in July asked Americans which issue was the most important facing the country. Health care was by far the top response; 4 percent said taxes. In the recent CBS poll, 70 percent said Congress should address other issues before passing a tax bill.

America has yet to see the full details of the bill, making it hard to gauge people's views on this exact piece of legislation (The Washington Post's Damian Paletta has a good rundown of what we know so far here).

What does have solid support is recent polls is tax cuts for small businesses and the middle and lower classes. But Gallup points out that in April of this year, 51 percent of Americans felt their taxes were "too high," far less than in 1985, when 63 percent felt that way.