Donald Trump may be losing the confidence of one of his strongest constituencies. After two years of unflagging support from America’s small business owners, a new Manta poll finds that their faith in the president is slipping.

From the very beginning of Trump’s campaign for president, small business owners were among his biggest and most consistent backers–an early bellwether of the underappreciated middle-class voters that surprised the political establishment. Starting in August 2015, poll after poll conducted by my company, Manta, found that Trump was the overwhelming favorite of entrepreneurs throughout the Republican primary and general election.

Immediately following the close November election, 58% of small business owners said they were happy with the outcome, and a whopping 89% were confident the new president would address their concerns as entrepreneurs. At the very top of that list: healthcare costs, cited as the number-one issue for the president to address by 75% of business owners.

Trump Promised to Bring Business Leadership to Washington

Trump’s outsider status certainly appealed to these business owners. They expected that he would be sympathetic to their challenges and more understanding of their needs than the usual crew of Washington bureaucrats.

Unlike most politicians, business owners felt Trump would know what it takes to build and run a business. On the campaign trail, Trump repeatedly promised to address Main Street’s biggest concerns: rising healthcare costs, complicated labor regulations, and a tax burden that was limiting growth.

As recently as January 2017, on the eve of the president’s inauguration, 68% of small business owners believed the Trump administration would positively impact their companies. Six months later, Manta’s new poll found that only 33% of business owners feel that way–a remarkable decline of more than 50% among his strongest supporters.

Small business owners demand results, and they just haven’t seen the accomplishments they expected from this administration.

Healthcare Uncertainty Continues to Frustrate Business Owners

Trump’s promise to repeal and replace the Affordable Care Act was a familiar refrain during the campaign. It certainly aligned with entrepreneurs’ top concern. Skyrocketing health costs are stifling growth and burying business owners, as employers and as individuals. The cost of compliance is rising, too, as many have been required to extend benefits to employees.

Business owners simply don’t know how to prepare for future healthcare guidelines. Meanwhile, insurers, citing uncertain outlooks of their own, are raising rates and pulling out of healthcare exchanges.

One thing business owners do know is the value of working together–accommodating difficult requests, making tough decisions, and finding mutually beneficial compromises with clients and partners. They expect no less of leaders in Washington, including the president.

Will Trump Find Success with Tax Reform Efforts?

Following the failure of healthcare reform, the debate to overhaul the federal tax code is slated to make headlines for the rest of the year. Hopefully the results won’t be as disappointing. After healthcare, small business owners consistently list taxes as one of their top concerns.

Tax cuts are always welcome, of course; many middle-income business owners pay onerous rates, from federal and state income taxes, to local property and inventory taxes, to overlapping jurisdictions that collect sales and use taxes. But just as pressing is the need to simplify tax regulations at every level.

Over one-third of business owners don’t even understand the tax deductions that are available to them. Not surprisingly, nearly two-thirds rely on a CPA or outside tax professional for help–an additional cost of compliance. America’s small businesses need a tax system that’s affordable, predictable and manageable so they can prepare their own financial plans with confidence and invest in their future growth.

There have been a few bright spots for entrepreneurs in the first six months of the Trump administration. The president put a freeze on additional federal regulations when he took office, and he suspended implementation of the Labor Department’s new overtime pay rules. The debate to raise the federal minimal wage, a cornerstone of the Democratic primary, has been largely silenced, although many business owners already pay above minimum wage.

Most business owners support Trump’s travel ban and immigration policies as well, even though they say these initiatives won’t directly affect their businesses.

The issues that impact their companies–and their bottom lines–still need to be addressed, however. America’s small businesses were built on a foundation of persistence and dedication. Every day entrepreneurs show up to work and get stuff done.

They expected that a business leader in the White House would work the same way. So far, they have been disappointed.

To regain the confidence of this key constituency, the president needs to get to work and make real progress on the economic and regulatory issues that are important to the small business owners who elected him.

The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.