WASHINGTON -- And yet his Austin-based handyman company, which operates in North Texas, might stand at the center of the business relief that Congress OK'd as part of a $1.5 trillion tax revamp.

"Intuitively, anyone would say that it's going to be good for business," Jenkins said.

For all of the attention to how the GOP's tax overhaul is affecting corporate giants like AT&T, American Airlines and others, lawmakers reached a far wider swath of the business world by providing a 20 percent tax break to "pass-through" operations like Jenkins'.

Those partnerships, sole proprietorships and S-corporations, which account for the vast majority of businesses, are so named because they pass through income to their owners' personal returns.

And while Republicans are staking that high-dollar tax cut on helping smaller businesses — with Jenkins, among others, planning to invest in facilities and hire more workers — the overall effect remains murky for many individual owners and the economy at large.

Critics point out that most pass-through income and, thus, most of the tax break, flows to the wealthy few. The new approach, which affects companies both big and small, could be rife for gaming. And the rules have added complexity that many businesses are still untangling.

"I can't say for sure if this tax bill is going to help this business or not," said Blake Woodard, the majority owner of Woodard Insurance in Fort Worth.

Most of the GOP's business focus in the tax debate went toward slashing the rate for "C-corporations" to 21 percent from 35 percent. Republicans are banking on that measure to drive substantial economic growth, though Democrats and some economists remain skeptical.

But such relief also spurred demand for a similar boost for millions of pass-through businesses.

Even though those entities already had the advantage of not facing the two levels of taxation that corporations can see, lawmakers pressed for more. And the GOP settled on a 20 percent deduction on most pass-through income, a break that came on top of cuts in the individual rates.

The perk exists for all such businesses with taxable income of $315,000 or less for joint filers. Above that threshold, the perk starts phasing out for doctors, attorneys and other service businesses. Other high-income operations face limits based on wages paid and capital assets owned.

But the overall pass-through landscape isn't so simple.

Some massive businesses, including President Donald Trump's real estate empire, organize as pass-throughs. And more than half of pass-through income flows to the select few who earn more than $500,000, according to a Tax Foundation analysis that has been echoed by others.