A Democrat-dominated city in a Blue State like Oregon never crowns with laurels a new Republican president replacing a Democratic one.

But the level of protest that will occur in Portland and around Oregon today and Saturday, from the boycott of Donald Trump's inauguration by three of the state's Congressmen to thousands marching through downtown streets and across city bridges, is unprecedented.

Protest organizers and political scientists say the record-high push-back is the result of at least two factors: A growing tradition of public demonstration in Portland and a new president whose rhetoric has been uniquely polarizing.

Top state officials, including Democrats Gov. Kate Brown and House Speaker Tina Kotek, will largely spend the day disregarding the pomp and circumstance 3,000 miles away as Trump is installed as the nation's leader. Closer to the ground, protest organizers say they'll gather thousands on the streets of Portland to draw the gaze of local and state leaders to their clarion call: resist Trump's agenda.

Gregory McKelvey speaks as protesters gather in Pioneer Courthouse Square on Thursday, Nov. 10, in Portland, the third night of protests over the results of the 2016 presidential election. (Mark Graves/Staff)

Gregory McKelvey, founder and organizer of Portland's Resistance, who formed the group after Trump's election victory, said he hopes to draw at least 10,000 protesters into the downtown core Friday. "We expect it to be peaceful and powerful," McKelvey said.

Teressa Raiford, leader of Don't Shoot Portland, a Black Lives Matter group, is organizing another protest timed to Trump's ascendancy. "We're sending a message -- stand up against racism and bigotry and all forms of violence against all people," she said.

Portland mayor Ted Wheeler said Wednesday he supports protesters' First Amendment right to assemble, but urged them to forgo the property damage and lone instance of gunfire that marked the large demonstrations days after Trump's victory. He has also directed police to keep marchers off freeways and from blocking MAX routes.

"We have an opportunity this week to show the world that we are very active and very engaged, but we are also peaceful," Wheeler said. "We are a community who will speak our minds. We will stand up against sexism, racism, xenophobia and homophobia."

The Portland Women's March, organized to show the new president widespread and heartfelt support for women's rights, could be the largest political march ever to occur in the city. Set for noon Saturday, the event could draw 20,000 or even 30,000 women, children and men.

Dana Plambeck, 43, of Portland, is bringing her 4-year-old son, Jack.

"I want him to see that you can peacefully voice your opposition to policies you believe are harmful," Plambeck said. "I want him to see that fighting and being a bully are not the only tools we have to make change."

Trump's divisive rhetoric has inflamed sensibilities -- and in turn united Portland's protesters, McKelvey said. They are black, Latino and white, gay and straight and transgender, the disenfranchised and disaffected, he said. And they are fighting to preserve what little ground they've gained during Barack Obama's presidency, he said.

"I think that if Trump ends up being as bad as we all expect him to be," McKelvey said, "we want to go down as resisting him at every point." When speaking of her aims, Raiford talked of establishing "a new political protocol."

Tens of thousands of Oregonians swamping Portland streets to oppose their president is a first since the Vietnam War.

"There have not been major protests before," said Jim Moore, political science professor and director of Pacific University's Tom McCall Center for Policy Research.

In 2001, the last time a Republican administration succeeded a Democratic one, 500 demonstrators gathered in Pioneer Courthouse Square during George W. Bush's inauguration, holding signs reading "Hail to the thief" and "Bush is not my president."

Now, as Trump takes the White House despite losing the popular vote and hyper-partisanship remains mainstream, Portland is cementing its protest culture, Moore said.

Local police have become more accustomed to protests since facing criticism for treatment of demonstrators at Occupy Portland marches five years ago. Since then, police have undergone more training in crowd control, as there have been more crowds to control. Portland Police Chief Mike Marshman said Wednesday, "The police bureau whole-heartedly supports First Amendment rights to protest."

U.S. Reps. Earl Blumenauer, Kurt Schrader and Peter DeFazio -- all Democrats -- will skip the inauguration, a move Moore cast as hyper-partisan. The governor will follow the day's events but "is keeping a full schedule," according to a spokesman.

To Raiford, it's not enough.

Teressa Raiford joined other members of Don't Shoot PDX in protest in the Pearl district, Nov. 25, 2016. Dave Killen/Staff

She is urging members of Don't Shoot Portland and its sympathizers to march along an east Portland route that passes the convenience store where a white supremacist, who is now charged with murder, allegedly mowed down and killed 19-year-old Larnell Bruce because he was black. She thinks Trump has given racists cover and even encouragement to speak up.

"I'm disgusted by the fact that some of our elected leaders from Oregon will be at this inauguration," she said. It's "disingenuous" that Democratic politicians like U.S. Sens. Ron Wyden and Jeff Merkley held a rally last week to oppose Trump's policies, but will not boycott his swearing-in, Raiford said.

U.S. Rep. Greg Walden -- Oregon's lone Republican congressman, and a powerful member of the House of Representatives -- will sit onstage and close to Trump during the inauguration, and attend lunch with the president afterward, according to his deputy chief of staff.

The demonstrations against the inauguration planned for Portland and other Oregon communities are an example of social movements sweeping the nation, said Pam Oliver, a University of Wisconsin sociologist who studies protests. This year's are bigger than usual, she said, because the nation is in the midst of a "protest wave" -- and liberals feel cheated out of the White House.

"You've got an election where pretty much everybody thought the Democrats were going to win, including a lot of Republicans," Oliver said. "The popular vote went Democratic. The election was very close. People are going to have a lot of pent-up energy and feeling robbed and not just willing to say 'Oh hell, we lost let's go home.'"

Protesting is also working its way into Portland's modern political heritage. Nationally, protests gained steam with the conservative Tea Party movement, Oliver said, pivoted with the 2010 midterm elections and went mainstream with the economic inequality movement Occupy Wall Street. More recently, protests sparked by high-profile police shootings of black people have grown into the Black Lives Matter movement, including a following in Portland.

Though critics dismiss the protests as likely to accomplish little, Trump's policy proposals are at the center of demonstrators' angst. Plans to build a wall on the southern border, repeal Obamacare and ban Muslim travel to the country draw ire from a wide spectrum of Americans and most of Portland.

For protests to ensue -- to bring communities together, draw media attention and pressure politicians -- is natural, Oliver said.

While Friday's protests are being orchestrated by seasoned demonstrators, their success depends on participation by throngs of protest neophytes.

Ralph Perez, a 39-year-old Portland social worker, said he plans to bring his wife and 11-year-old daughter to Friday's protests.

Their family is political, Perez said, but Trump's election sparked in them an activist streak. He and his wife plan to pen letters to their congressmen for the first time, urging opposition to Trump's policies.

"We pick these individuals to speak for us as a city, as a state, as a people," said Perez, who is of Puerto Rican descent. "We need to make sure they are held accountable as well."

As for the protest, Perez said he has high hopes it will be a peaceful gathering of like-minded people.

"We're making our voices heard," he said. "We won't be quiet."

-- Gordon Friedman

gfriedman@oregonian.com; 503-221-8209

Lynne Palombo, Jessica Floum and Lizzy Acker of The Oregonian/OregonLive contributed to this report.