A pro-Trump nonprofit released polling Thursday finding that Democratic Sen. Joe Donnelly would pay a political price in his home state of Indiana if he opposes the GOP tax reform effort.

America First Policies, a group run by former Trump campaign officials, found that 41 percent of Indiana voters would be less likely to vote for Donnelly if he opposed the tax plan, versus 33 percent who said they would be more likely.

Donnelly is up for re-election next year. President Trump won Indiana by nearly 20 percentage points.

The poll also found overwhelming dissatisfaction with the current tax system, at nearly 70 percent. Four in five men disapprove of the current code.

"In states like Indiana, voters are keeping a close eye on their leaders in Congress and expecting them to support a tax reform plan that benefits middle America and the middle class," said Brian O. Walsh, the group's president.

In general, public polling reveals ambiguous attitudes toward Republican tax goals.

Both Trump and Vice President Mike Pence traveled to Indiana last month with Donnelly to try to win his vote.

For his part, Donnelly has signaled that he is open to working with Republicans but does not yet support the tax plan.

"Right now, the only plan out there is missing a lot of important details," Donnelly said last week. "And like most Hoosiers, I'm not gonna buy a car before kicking the tires."

Republicans are hoping to have a few red-state Democratic senators join them in voting for tax legislation — or to exact a political price from them if they vote "no."

"That would be wonderful," Trump said of Democratic support Wednesday in a tax reform speech in Harrisburg, Pa. "But sadly, the Democrats have become obstructionists."

America First Policies' survey included 400 likely voters.

This post has been updated to correct the identification of America First Policies.