Republicans have persuaded themselves that keeping control of Congress in 2018 depends on passing their tax-cut plans. And it could work out that way.

But a national poll released today shows that President Donald Trump and his party have an enormous amount of work to do. Right now, the tax bill only adds to their burdens.

The telephone survey of 1,508 voters was conducted by Quinnipiac University from Nov. 29 to Dec. 4 as the Senate pushed through its tax-cut bill, setting up conference committee negotiations on a final version with the House. It carries a margin for error of 3.1 percentage points.

The poll shows Americans oppose the Republican tax-cut effort by nearly two-to-one, as 29 percent approve and 53 percent disapprove. That's a worse showing than Obamacare ever recorded, and more unpopular than former President Bill Clinton's tax increase plan when it passed in 1993.

Just as daunting are results showing that most Americans don't buy the core arguments Republicans have offered for their plans. Moreover, debate over the issue has harmed the party's reputation.

Trump and Congressional leaders say the plan will, on average, cut taxes immediately for Americans in every income category. But the Quinnipiac poll shows that three of four Americans, including most Republicans, believe the tax plan will either raise their taxes or not affect their tax bill very much.

Trump and Congressional leaders say they designed their plan to benefit middle-class families. But 64 percent of Americans, including one-quarter of Republicans, say the wealthy will benefit most.

Trump and Congressional leaders argue that their plan will create jobs and boost economic growth. But 53 percent of Americans in the Quinnipiac poll say it won't.

Trump and Congressional leaders insist their tax-cut plan will reduce the national debt, but the top tax experts who advise Congress say it will actually add $1 trillion to the debt. In the poll, 58 percent say they would be less likely to support the plan if they knew it increased the debt.

As a result, consideration of the matter has handed Democrats a fresh advantage over Republicans. In August, Americans split evenly over which party handles tax issues better. Now, Democrats hold an eight-percentage-point edge, 47 percent to 39 percent.

That adds to advantages Democrats already hold as midterm elections approach. Most significant is Trump's historic weakness.

With just 35 percent approval in the new Quinnipiac poll, he is the least popular first-year president since polling began. By two to one – 52 percent to 25 percent – Americans say they feel embarrassed rather than proud that Trump is president.