Republican Sen. Ron Johnson believes it would be easier for the Senate to focus on tax reform instead of healthcare.

The Wisconsin senator is the latest lawmaker to cast doubt on the prospects for getting Obamacare repeal done in the Senate quickly.

"I think tax reform is an easier lift," he told the radio station AM 970 The Answer. "There are a number of pretty good proposals out there."

Johnson speculated that getting Obamacare passed is going to be harder than it looks. Johnson has been pushing for a short-term bill to stabilize Obamacare's exchanges while working on long-term reform.

"We may have to break this into two pieces," he said.

He said the Senate should take its time to put together a healthcare bill that "restrains the cost of healthcare."

Senate committee and leadership staff is putting together legislative text that outlines the ideas being bandied about by a group of more than a dozen senators.

But the text is expected to be just a draft and reference point for continuing negotiations. Major rifts in the GOP conference remain over Medicaid spending and how generous tax credits should be.

Johnson isn't the only senator to vocalize his skepticism on whether a deal gets done on healthcare soon.

Sen. Richard Burr, R-N.C., recently said he also doubts that healthcare gets done this year at all.