(CNN) Lobbyist Pamela Lopez walked into a bathroom and felt the rush of a large man behind her.

He pushed her inside, she said, and before Lopez could turn around she heard the door lock.

The man began to masturbate and told her to "touch his penis," she told CNN. "I was terrified. I backed myself against the wall and thought, 'What am I going to do?'"

Lopez's story sounds similar to the ones told by more than 40 women over the last two weeks accusing movie mogul Harvey Weinstein of sexual harassment or assault. Lopez was inspired by those women to speak up.

The man Lopez accuses of assault, she says, is a current California state legislator. She's one of nearly 150 women who have signed a public letter decrying a culture of sexual harassment in California's state politics, which takes root when lawmakers, staffers and lobbyists descend on Sacramento each year for the legislative session.

"It becomes a summer camp-like atmosphere," said Adama Iwu, a lobbyist for Visa who started the campaign to expose harassment. "It's difficult to create boundaries when these men are basically your co-workers, having breakfast, lunch and dinner with you."

In Lopez's case, she attended a 2016 party at a Sacramento bar in hopes of making connections that would pay off later. She briefly greeted the legislator, whom she won't identify publicly, but had no other contact with him until she says he forced her into the bathroom.

"Years before, I was the victim of rape, and I thought, 'Oh here we go again,'" she said.

Lopez says she firmly told the man, "No, I'm not going to touch you," causing him to plead that she at least touch another part of his body as he gratified himself.

Lopez refused, and says that after he finished she insisted they "walk out that door" and return to the party.

"He said, 'OK, don't tell anybody this happened.'" Lopez recalls. "I felt like he'd done this before; he wasn't shy."

Lopez says she's not afraid to speak up now because she is a high-level partner at the K Street Consulting firm, and has the support of her colleagues.

But others don't have that power, Iwu said, which is why she decided it was time to go public.

Adama Iwu, a lobbyist for Visa who started a campaign to expose sexual harassment in Sacramento.

'We Said Enough'

Iwu's open letter, first published in the Los Angeles Times on Monday, was inspired by an incident just over a week ago when a man "touched her inappropriately" at a political event, she said, and no one else called out the behavior.

"We had just had a conversation about Harvey Weinstein, and for this to happen right in front of them and not recognize it, it was egregious," she said.

Her letter, signed by lobbyists, staffers and legislators, states, "Each of us has endured, or witnessed or worked with women who have experienced some form of dehumanizing behavior by men with power in our workplaces. Men have groped and touched us without our consent, made inappropriate comments about our bodies and our abilities...

"Why didn't we speak up? Sometimes out of fear. Sometimes out of shame. Often these men hold our professional fates in their hands," the letter explains. "We're done with this."

A website titled "We Said Enough" was set up to invite women to tell their own stories of harassment. Iwu said she's already heard from women from Hawaii to Washington, D.C., and will publish their anonymous accounts on the site.

"This isn't about a couple of bad actors," Iwu said. "It's about shifting the entire environment."

Some in legislature 'nervous'

Organizers of "We Said Enough" say the reaction from men in the state Legislature has been mostly supportive, though Iwu acknowledges nerves are rattled.

"We've heard that men here are nervous, that people don't want to be falsely accused," she said. "That's not something we want to happen, either."

Iwu said the "We Said Enough" movement is not designed to "out" men, but to shift overall culture. She adds that naming specific accusers could have negative consequences for the women involved.

"It is not the job of the victim to come forward and be further victimized, because we know that happens," Iwu said. "Why is it always on the women to change things?"

In a statement, California state Senate leader Kevin de Leon applauded the women for coming forward, adding that "the Senate is reviewing its procedures... to ensure we are doing all we can to promote a safe workplace... protect victims who come forward and to demand accountability from those who violate these policies."

As for Lopez's claim of assault by a legislator, Daniel Alvarez, secretary of the state Senate, called it "startling and unsettling." In a statement, he added that even though there is no formal complaint, "We take the allegation very seriously, and we are currently reviewing the matter."

For Lopez, she said she continues to see the man she says assaulted her, and calls his lack of apology "dehumanizing."

"They know they can get away with it and they don't owe you the slightest apology," Lopez said. "It's a challenge many women in politics have to deal with."