SEATTLE — Keli Carender has a pierced nose, performs improv on weekends and lives here in a neighborhood with more Mexican grocers than coffeehouses. You might mistake her for the kind of young person whose vote powered President Obama to the White House. You probably would not think of her as a Tea Party type.

But leaders of the Tea Party movement credit her with being the first.

A year ago, frustrated that every time she called her senators to urge them to vote against the $787 billion stimulus bill their mailboxes were full, and tired of wearing out the ear of her Obama-voting fiancé, Ms. Carender decided to hold a protest against what she called the “porkulus.”

“I basically thought to myself: ‘I have two courses. I can give up, go home, crawl into bed and be really depressed and let it happen,’ ” she said this month while driving home from a protest at the State Capitol in Olympia. “Or I can do something different, and I can find a new avenue to have my voice get out.”

This weekend, as Tea Party members observe the anniversary of the first mass protests nationwide, Ms. Carender’s path to activism offers a lens into how the movement has grown, taking many people who were not politically active — it is not uncommon to meet Tea Party advocates who say they have never voted — and turning them into a force that is rattling both parties as they look toward the midterm elections in the fall.