The maneuvering in response to last week's passage of a multi-billion corporate tax increase heated up today in Salem.

On May 13, Democrats convinced Senate Republicans to return to work so the full Senate could vote on House Bill 3427, the "Student Success Act" which will levy a gross receipts tax on Oregon businesses and provide a modest reduction in the personal income tax rate paid by most Oregonians.

The bill, which Gov. Kate Brown has already signed into law, is expected to raise more than $1 billion in new revenue annually and is supposed to be spent on schools.

Many Republicans oppose the tax and have begun talking about gathering the signatures necessary to refer it to the ballot. (Voters decisively rejected a larger, more narrowly based gross receipts tax in 2016.)

In recent election cycles, instead of hiring human signature gatherers to approach voters in person, initiative supporters have begun relying heavily on electronic signature sheets, which can be printed from the internet.

In March, the Senate Rules Committee heard Senate Bill 761, which would require that voters could only sign electronically-generated sheets if they'd printed them themselves. (In the past, for instance, advocacy groups circulated signature sheets in newsletters, encouraging readers to sign.)

In testimony then, public interest lawyer Dan Meek, testifying on behalf of the Progressive Party, called the initial version of SB 761 "voter suppression."

Today, Senate Majority Leader Ginny Burdick (D-Portland) introduced an amendment to the bill which would prevent voters from using electronic signature sheets in any fashion for the next four years—long past the window for referring the new tax.

Secretary of State Bev Clarno, a Republican, testified against the amendments, agreeing with Meek's original point that the bill could disenfranchise voters and noting that the validation rate for electronic signature sheets is far higher than the validation rate for human-gathered signatures.

"Eliminating e-sheets denies Oregonians the ability to participate in the petition process, particularly if a person lives in a rural community or is home bound," Clarno said in written testimony. "Oregon has a vibrant culture of voter engagement and outreach and this is a step in the wrong direction. Our initiative and referendum petition process allows each citizen to make their voice heard and this bill would require a citizen to rely on signature gatherers to participate. This is not feasible for many Oregonians around the state. Lastly, our office has found that e-sheets have a higher validity rate than regular petitions, and we are not aware of any abuses."

Other Republicans, including the lobbying group Oregon Manufacturers and Commerce, which opposed the new tax, don't like the original bill or Burdick's amendment.

And it's not only Republicans who are pushing back.

Sal Peralta, the secretary of the Independent Party of Oregon, also criticized today's amendment.

"I testified against the underlying bill when it came before your committee in March," Peralta said. "That bill sought to restrict the rights of voters to sign single-signature sheets that they, themselves, did not print.This -3 amendment takes the original legislation and makes it a bit more cynical. It declares an emergency that suspends the right of anyone to use e-signature sheets for four years. It is hard for me to see this as anything other highly cynical political maneuver intended to make it harder for initiative petitions to qualify for the ballot."

Through a spokesman, Burdick said critics are misguided and ignoring potential abuses that electronic signature sheets can facilitate.

"In 2007, a new law allowed a voter to print an electronic signature sheet for an initiative petition," Burdick said in a statement.

"Since then, the secretary of state has broadened the use of electronic sheets, creating loopholes that have allowed for bad actors to circulate tall stacks of printed electronic signature sheets. SB 761 will place a time-out on the use of electronic signature sheets so that we can ensure the integrity of the initiative system."