Fresh polling commissioned by an organization supportive of President Trump revealed the political challenges Republicans face in selling their tax overhaul to a skeptical public.

The survey for 45 Committee, a political nonprofit, found support for tax reform and tax cuts generally. But just 40 percent support the tax reform language poised to clear Congress as early as Tuesday, with 49 percent opposing. Only after poll respondents were provided details and messaging did their opinions improve.

"In response to the question: 'Do you support or oppose the Republican plan to reform the federal tax code and cut personal and business taxes? Forty percent indicate their initial support and 49 percent are opposed. When introduced to key features of the bill, support improves to 43 percent support/51 percent oppose. Intensity in strong support of the bill also increases from 20 percent to 27 percent," read the polling memo from Public Opinion Strategies, the GOP firm that conducted the survey.

"Voters in Republican-held congressional districts are supportive of the plan, 47 percent support/42 percent oppose, on the initial ballot. Support reaches 50 percent in these districts after hearing the messages on both sides of the tax reform debate," the memo read.

Republicans have been under pressure to accomplish tax reform, needing to keep a major campaign promise from 2016 and justify the party's full control of the government in the wake of the collapse of their effort to repeal and replace Obamacare. But now Republicans face the challenge of convincing a suspicious electorate to like the bill they passed.

Polls show the bill to be broadly unpopular. Worse for Republicans, GOP-friendly voters on the traditionally conservative suburbs are leery of the legislation because of provisions they believe will raise their taxes. One of the problematic measures would cap how much money in state and local taxes Americans can deduct from their federal tax liability.

This could complicate the Republicans' efforts to hold their majorities in the House and Senate, given polling that suggests the Democrats stand to make significant gains. But according to the Public Opinion Strategies poll for 45 Committee, passing the tax bill could improve the GOP's position.

"On an initial generic ballot, the unnamed Republican trails the Democrat by 12 points (37 percent - 49 percent). After hearing the debate about the tax reform bill, the GOP generic ballot deficit closes to 8 points (41 percent -49 percent,)" the memo read. "Importantly, there is also good movement among some key sub-groups on the generic ballot, including a bigger margin in Republican-held districts."

The national poll was in the field Tuesday through Saturday and surveyed 800 "voters," including 40 percent via cell phone. The error margin was 3.46 percentage points.