WASHINGTON -- Forget about watching the fireworks. Some Americans are determined to be firecrackers themselves.

Walter Ducharme, 76, of Cambridge, is celebrating Independence Day by practicing his right of expression, delivering a silent but explosive message to President Bush at his home.

"Impeach Bush" is emblazoned in white letters across Ducharme's black T-shirt. The buzz-haired man stands out like an exclamation mark amid the crowd clambering around the fence on the north lawn of the White House snapping souvenir pictures.

"It's one of my goals in life to see him in jail," said Ducharme, an antiwar activist who plans to join a large rally today in which thousands of people are expected to fast for at least 24 hours.

"Fourth of July is supposed to spell independence from a king, a ruler," he said, the black iron fence that cordons the White House grounds a few feet away. "I feel very empowered by being here."

The president's pursuit of expanded executive powers to battle terrorism, coupled with erroneous -- opponents say selective -- intelligence used as the basis for invading Iraq, is fuel for critics.

They are using the Fourth of July and its inherent messages of patriotism and freedom to get involved along the fringes of the democratic process. Their holiday parades won't feature brass baritones and rolling floats, but loudspeakers and calls to action.

"In my spare time, I protest," said Mike Hearington, 52, a district manager with a sales company in Memphis, Tenn. "I'm so against what we're doing, I want to do my part."

White House tourists snapped pictures of Hearington and his 9-year-old son, Connor, both of whom held the corners of a tablecloth-size sheet with the painted words: "Impeach Bush" with a plus sign that represents Vice President Dick Cheney, said Hearington, a former Vietnam-era veteran.

Just then, an officer with the Secret Service Uniformed Division asked the Tennessean for his name, writing it down in a pocket notebook.

Moments later, a man with a differing political persuasion parted from the crowd near the White House fence and told Hearington and his son: "It's not going to happen, guys. Wish on something better."

There's no lack of wishes along that blocklong strip

Jay McGinley, 54, has sat along that pedestrian street for 22 hours a day for the past two months, he said, leaving only long enough to recharge the battery of his laptop computer at a public library. He sleeps on park benches.

He's never been an activist. Then came the Darfur genocide. He sold his car, quit his job and came here not to protest, he said, but to inform other Americans about the ongoing atrocities in Sudan.

"We've turned democracy into a spectator sport," McGinley said, wearing clean khaki pants, a tucked-in plaid shirt and a North Face cap. "I think I'm having more of an impact here than if I was still running a retail store in Philadelphia."

On each side of him were two large posters of suffering children. He sat under a blue and yellow umbrella to block the sun, using his laptop to blog about the violence that has killed hundreds of thousands of civilians.

Sometimes, the protesters' expressions explore the boundaries of constitutionally provided freedoms, an experiment embarked upon 230 years ago today when 13 colonies declared themselves independent of England's monarchy.

Ducharme and about 350 others were arrested in the spring outside the north lawn of the White House when the group, led by Cindy Sheehan, whose son died in Iraq, refused to disperse.

"I'm very proud of that," he said.

A former program manager for an emergency men's shelter in downtown Boston, Ducharme is so passionate about ending the war that he briefly choked back tears when explaining his convictions. But there's a lighter side, too.

"A Canadian friend of mine made me promise to come to the White House and give George the finger," he said, laughing. "I'm looking for someone to take my picture."

Evan Lehmann's e-mail address is elehmann@lowellsun.com.