By Ian Simpson
WASHINGTON (Reuters) - Washington turned into a virtual fortress on Thursday ahead of Donald Trump's presidential inauguration, with police ready to step in to separate protesters from Trump supporters at any sign of unrest during the festivities.
Some 900,000 people, both Trump backers and opponents, are expected to flood Washington for Friday's inauguration ceremony, according to organizers' estimates. Events include the swearing-in ceremony on the steps of the U.S. Capitol and a parade to the White House along streets thronged with spectators.
On Thursday, police cars lined much of Pennsylvania Avenue, the parade route, as workers unloaded crowd control fences from flatbed trucks, erected barricades and marked off pavement with tape.
The number of planned protests and rallies this year is far above what has been typical at recent presidential inaugurations.
U.S. Department of Homeland Security Secretary Jeh Johnson said police aimed to keep groups separate, using similar tactics as employed during last year's political conventions.
"The concern is some of these groups are pro-Trump, some of them are con-Trump, and they may not play well together in the same space," Johnson said on MSNBC.
About 30 groups totaling 270,000 people have received permits to stage demonstrations, both for and against the New York businessman in Washington around the inauguration. That number includes some 200,000 people who police say they expect to attend Saturday's Women's March on Washington, an anti-Trump protest.
Trump opponents have been angered by his comments during the campaign about women, illegal immigrants and Muslims and his pledges to scrap the Obamacare health reform and build a wall on the Mexican border.
The Republican's supporters admire his experience in business, including as a real estate developer and reality television star, and view him as an outsider who will take a fresh approach to politics.
Bikers for Trump, a group that designated itself as security backup during last summer's Republican National Convention in Cleveland, is ready to step in if protesters block access to the inauguration, said Dennis Egbert, one of the group's organizers.
"We're going to be backing up law enforcement. We're on the same page," Egbert, 63, a retired electrician from Harrisburg, Pennsylvania, said at the group's site along the parade route.
About 28,000 security personnel, miles of fencing, roadblocks, street barricades and dump trucks laden with sand are part of the security cordon around 3 square miles (almost 8 square km) of central Washington.
A protest group known as Disrupt J20 has vowed to stage demonstrations at each of 12 security checkpoints and block access to the festivities on the grassy National Mall.
Police and security officials have pledged repeatedly to guarantee protesters' constitutional rights to free speech and peaceable assembly.
Aaron Hyman, fellow at the National Gallery of Art, said he could feel tension in the streets ahead of Trump's swearing-in and the heightened security was part of it.
"People are watching each other like, 'You must be a Trump supporter,' and 'You must be one of those liberals,'" said Hyman, 32, who supported Democrat Hillary Clinton in the November election.
Anti-Trump protester will stage at a rally in New York on Thursday evening. Mayor Bill de Blasio, filmmaker Michael Moore and actor Alec Baldwin, who portrays Trump on "Saturday Night Live," will take part in the event outside the Trump International Hotel and Tower.
One of the Washington protests will feature a haze of pot smoke as pro-marijuana activists light up to show their opposition to Trump's choice for attorney general, Senator Jeff Sessions, a critic of legalization.
Friday's crowds are expected to fall well short of the 2 million people who attended Obama's first inauguration in 2009, and be in line with the 1 million who were at his second in 2013.
Security officials have eased a ban on umbrellas at the ceremony due to a rainy weather forecast, allowing people to use small umbrellas.
(Additional reporting by Susan Heavey; Editing by Bill Trott and Alistair Bell)