After pulling an all-nighter Thursday, state lawmakers approved a substantially loosened version of a controversial amendment aiming to limit government spending and cut taxes, Friday.

In a 50-48 vote, the Republican-dominated Assembly approved the amendment around 5 a.m. Friday after hours of Democratic floor opposition and private Republican caucusing.

Following a 66-32 vote to reject a stricter version of the Taxpayer Protection Amendment, Republicans privately drafted another version without subjecting it to public review.

While Democrats criticized the bill's back room drafting, Republican supporters maintained the amendment still accomplishes their objective to reform government spending.

"[This] is the most comprehensive government reform package that has ever been passed in this state," amendment proponent Rep. Jeff Wood, R-Chippewa Falls, said.

But other Republicans — namely the original TABOR founder Rep. Frank Lasee, R-Bellevue, said the passed amendment does not provide the taxpayer protection it lauds, as numerous exemptions to spending limits were made in an effort to coerce passage.

While Lasee's plan would have applied to both state and local governments, the new amendment would exempt local governments and certain state accounts from revenue limits.

Calling the new plan the "Swiss cheese amendment," Lasee criticized his Republican colleagues for drafting a loophole-filled amendment, which he said fails to provide taxpayers with any meaningful tax relief.

"This whole thing was about appearance over substance," Lasee said. "And this was so that the Legislature could look like they were doing something, when in fact, they weren't doing anything at all."

Wood, however, said although amendment supporters were forced to compromise to reach a majority vote, the measure still offers substantial progress. He added placing spending restrictions on the state mark a big step forward, as local limits can still be enacted by state statute.

But as Lasee and Wood continued to disagree over the quality of the passed amendment, Democrats continue to express opposition to any tax reform measure proposing to amend the Wisconsin Constitution, especially in what they see as such a hasty manner.

According to Assembly Minority Leader Rep. Jim Kreuser, D-Kenosha, in a release, Republicans in the Assembly are failing the state by ignoring the more than 80 groups registered against the amendment.

"Rather than focusing on the glaring need for health care reform, the state Assembly has devoted more than a month of hearings and several days of marathon caucus meetings to an issue that barely passed the Assembly and is dead on arrival in the Senate," he said.

Lasee, however, maintained the importance of passing a taxpayer protection amendment, adding a majority of the state's citizens support limits on state spending.

"The government should serve us and not the other way around," he said, adding the Legislature would be denying the public by not allowing citizens to vote on a taxpayer protection measure.

Lasee added he hopes to continue to work with Senate members to help them draft substitute amendments to strengthen the measure. While senators are expected to consider the bill this week before session ends Thursday, critics doubt enough Senate support exists to pass the measure.

If passed by the Senate, the amendment would also have to pass through the next legislative session and through a statewide referendum before it could become law.