CLEVELAND, Ohio -- The Democratic activists and concerned Clevelanders who gathered here Thursday night at the St. James AME Church knew Sen. Rob Portman wouldn't show.

He had been invited, yes. But when organizations firmly aligned with the political left -- such as the progressive staple MoveOn.org and the quickly emerging Indivisible -- are listed as the event's hosts, a conservative Republican such as Portman isn't likely to accept.

Portman wasn't there in person, but his likeness was everywhere. There was the huge cardboard cutout of his head at the front of the church. A sign with his face plastered next to a chicken. "Missing" posters and milk cartons. Boos erupted at the first mention of his name.

"Even though Senator Portman is absent today, we will ensure he hears what we have to say," Rachael Sarkissian, founder of the IndivisibleCLE chapter, told the more than 300 attendees jammed into the pews and balcony. "We will continue to push him to do the right thing."

The evening offered a peek into the discontent brewing in the early days of President Donald Trump's administration. Indivisible and other groups are calling on members of Congress to oppose -- or "resist," to use the phrase the movement's followers prefer -- Trump's agenda.

The two-hour forum featured fiery speeches and folk music singalongs. At one point attendees stomped their feet so hard that the cardboard Portman fell to the floor, provoking wild cheers.

Representatives from Black Lives Matter and Organizing for Action, a group that traces its roots to former President Barack Obama's campaigns, were among those who addressed the crowd. They advocated for social justice and the continuation of Obama's health care policies.

Some compare the movement to the Tea Party's rise eight years ago, following Obama's election. Many Republicans see a well-coordinated, well-funded and largely non-organic attempt to make mischief. (Of course, Democrats said the same about the Tea Party.)

"I am not a paid protester," Suzy Scullin, one of the organizers of Thursday's event, told the audience. "And I don't think any of you are paid protesters, either."

Angry constituents are turning up at public events to grill lawmakers in YouTube-worthy confrontations. And Democratic activists have been pressuring officeholders to attend town hall-style meetings like the one that Portman's opponents held Thursday in Cleveland.

"Rob won [re-election] by 21 points because he is an independent voice who effectively represents the interests of all Ohioans," his press secretary, Emily Benavides, said in an emailed statement Thursday. "He welcomes the increased engagement from his constituents, both on the Right and the Left, and will continue to have an active schedule in Ohio this year, above and beyond the 475 events he held last year. The opinion of every constituent is valued."

Judy Kruger and Casey Ross, both of Oberlin, crisscrossed the state this week in hopes of questioning GOP officeholders. "We are becoming rabble-rousers," said Ross, 67.

On Monday they traveled to Marion, where U.S. Rep. Jim Jordan of Champaign County took questions from critics at a Presidents Day event. "I give him credit for that," said Kruger, 80.

Both wondered why Portman wouldn't do the same.

Portman's schedule this week included facetime with constituents, but mainly in controlled settings such as a Whirlpool plant in Clyde and a substance abuse counseling center in Holland. On Friday he plans to discuss the heroin epidemic during a visit to Columbus State Community College and lead a "tax reform roundtable" at the Greater Cleveland Partnership.

He also spoke Wednesday at a Lincoln Day dinner hosted by the Sandusky and Seneca County Republican parties. Democrats who bought tickets for the fundraiser ultimately received refunds once organizers became aware of their party affiliation. Benavides disputes an account to the Columbus Dispatch by the Seneca County GOP treasurer, who told the newspaper that it was the senator's staff made the call to dump the Democrats.

Scullin was among those who attempted to attend the Wednesday dinner. She said her efforts earned her an audience with a Portman aide who was open to the idea of a future meeting.

"I think that's one of the best things we could have hoped for out of the evening," she said. "Though it's not much."