SALEM — Republicans in the Oregon Senate fled the Capitol on Monday to stop Democrats’ bill to cap greenhouse gas emissions after the plan cleared a legislative budget committee earlier in the day.

At Monday’s 11 a.m. Senate floor session, just one Republican showed up: Sen. Tim Knopp of Bend. Democrats waited as sergeants at arms searched Capitol offices to see if they could round up any other Republicans. But they were unable to find any, so Senate President Peter Courtney, D-Salem, adjourned the chamber until Tuesday.

Senate Republican Leader Herman Baertschiger Jr. of Grants Pass has been talking with Courtney on a daily basis and “did leave the door open that maybe they’d come back,” Courtney told reporters. But he conceded it’s unclear whether Republicans would return for any deal short of referring the climate bill to voters.

Under the state Constitution, a two-thirds majority of the Senate must be present to conduct business including voting on bills. That means Democrats, despite their supermajority, need at least two Republicans to be present. Courtney said he does not plan to ask the governor to send the state police looking for the Republicans, and Brown said without a request from Courtney she lacks the authority to do so.

Senate Republicans shut down business twice last year by walking out, first to stall a business tax and kill vaccine and gun control bills, then to help kill the 2019 version of cap-and-trade. Earlier this month, House Republicans boycotted an evening floor session to pressure Democrats to slow down the pace of lawmaking.

The earliest the cap-and-trade bill could come up for a Senate floor vote is Wednesday, according to Senate Democrats.

Democratic lawmakers have taken a measured, deferential tone in recent weeks, in an apparent attempt to control tensions at the Capitol. But that ended when Republicans followed through on their widely anticipated walkout Monday.

“If (Senate Republicans) don’t like a bill, they need to show up and change it or show up and vote ‘no,’” Gov. Kate Brown said in a during a briefing with reporters. Instead, the senators “have chosen to take a taxpayer funded vacation … Oregonians should be outraged and I am, too.”

Senate Majority Leader Ginny Burdick, D-Portland, issued a statement saying “Walking out on the job is a dereliction of duty” and also describing Republicans’ boycott as “dishonorable and disrespectful.”

House Speaker Tina Kotek, also a Portland Democrat, called the walkout “a crisis for our democracy. This is not a game. Voters elected us to do our job. The members who refuse to show up and do their jobs are saying to a large majority of Oregonians: your vote doesn’t matter.”

According to the most current available estimates from the Census Bureau, for 2014 through 2019, the 11 Republicans who walked out represent just 36% of Oregon’s population.

In a statement, Baertschiger blamed the GOP’s boycott in part on a parliamentary move by Courtney. With the climate bill before the Legislature’s Joint Committee on Ways and Means early Monday, Courtney joined the committee to provide a crucial vote to pass it out, because one of its Democratic co-chairs, Sen. Betsy Johnson, voted with Republicans first to refer the measure to voters, then to kill it. Courtney knew his vote would be needed to make both of those votes go Democrats’ way.

Republicans took Democrats to task for the move, but it was clearly allowed under the Senate’s adopted rules and longstanding precedent, Secretary of the Senate Lori Brocker testified.

“Senator Courtney’s actions leave no other option for Senate Republicans but to boycott and deny quorum because cap and trade is on the way to the Senate floor,” Baertschiger said in the written statement. “Democrats refused to work with Republicans and denied every amendment that was presented. Pay attention Oregon – this is a true example of partisan politics.”

The GOP had anticipated Courtney might replace Johnson of Scappoose, a cap-and-trade opponent, for the vote, as he did last year on a similar climate plan. Instead Courtney left Johnson on the committee and added his own vote.

Senate Bill 1530 would set a gradually more stringent cap on statewide carbon dioxide emissions and require polluters from the transportation fuels, utility and industrial sectors to acquire “emissions allowances” to cover every metric ton of their emissions.

Democrats have made concessions to Republicans and other opponents of the bill, including exempting a geographically large portion of the state from fees on gas and diesel indefinitely. But Democrats, who hold supermajorities in both chambers, have also voted down numerous amendments proposed by Republicans.

Other Senate Republicans also issued statements explaining their decision to leave and stop business in the Senate. Sen. Lynn Findley, of Vale, said he was following his constituents’ wishes by fleeing Salem.

“It is my job to represent them—not special interests or out-of-state deep pocket donors—and that’s what I am doing,” Findley said. “If my colleagues will not allow for a fair process in the building, then I will represent my constituents from outside the building.”

Sen. Kim Thatcher, a Keizer Republican who is also running for Secretary of State, said in a press release that lawmakers should refer the cap-and-trade plan to voters. The “vast majority” of people who have contacted Thatcher told her cap-and-trade “will do more harm than good,” she said. “Sometimes a boycott is the best way to stop bad laws from happening to good people.”

Amid news of the walkout, public employee unions and other groups including the pro-cap-and-trade organization Renew Oregon suggested in a press release that they might target Republicans in swing districts who left the Capitol. It named Thatcher and Salem Sen. Denyc Boles and quoted Allison Seymour, a nurse in Boles’ district. “Sen. Boles and her fellow absent senators should come back to work and fulfill their duty to Oregonians,” Seymour said in the press release.

In Boles’ district, registered Democrats outnumber Republicans by a very narrow margin and there are more unaffiliated voters than members of either party. Republicans hold a tiny edge in Thatcher’s district, with unaffiliated voters similarly outnumbering voters registered with either party.

As for Tim Knopp, the lone Senate Republican who showed up for the floor session Monday, there are several thousand more registered Democrats than Republican voters in his district and also a large share of unaffiliated voters. Knopp remains opposed to the climate change bill but stayed at the Capitol to push for some of his own priorities including changes to a business tax Democrats passed last year and a bill to freeze property taxes for older Oregonians.

“I think I’m representing my district, that they feel like they need to have somebody here to work on those issues and those issues are important to me,” Knopp said, adding that “my decision is day to day as to whether or not I’ll be here.”

Factors Knopp is weighing include “how are the Democrats treating the minority, how are they treating our constituents, are they listening. And right now, I think they’re trying to listen.”

With two weeks left in the short 35-day session, many significant policy bills such as plans to trim a tax break for wealthy investors, ban the pesticide chlorpyrifos, outlaw discrimination based on hairstyles historically associated with race and require safe storage of firearms have yet to pass the Legislature.

Lawmakers’ plan to provide $45 million to open homeless shelters and to allow them to be located regardless of zoning, planning and design rules has bipartisan support, but it has yet to receive a floor vote in either chamber. A bill to permanently increase the statewide tourism lodging tax, in part to raise $20 million for the 2021 world track championships in Eugene, passed the House but still needs approval in the Senate.

The governor’s nearly $12 million long-term relief package for eastern Oregon communities hit hard by flooding won’t pass unless senators return to pass this and other budget priorities, and neither will legislation that’s part of a logging practices deal announced earlier this month between timber companies and conservation groups.

And although legislative leaders want to allocate roughly $500 million to address needs in the state child welfare program, forestry department, local corrections agencies and state hospital, they can only do so with quorums in both chambers. Ditto for issuing around $300 million in bond-backed debt sought by universities for building projects.

Brown left open the possibility she might call lawmakers back in a special session, and Courtney said he’s holding out hope Republicans will return before the March 8 deadline in the current session and take up those important bills, as they did in 2019 during a marathon final weekend of the session. “I want to continue to work very hard on all these other things so that if we ever did come back, we could really run the budgets and run everything as fast as we could the way we did on that famous Sunday in the general session when we passed I don’t know how many bills in two hours.”

Editor Betsy Hammond contributed to this report.