The shadows of bystanders are cast on the side of a balloon Saturday during the Albuquerque International Balloon Fiesta, in Albuquerque, N.M.

Albuquerque, N.M. ? Hundreds of thousands of potential voters will pass through Albuquerque over the next several days. Their purpose: to eat too many breakfast burritos as they sip hot chocolate and take in the spectacle of the annual international hot-air balloon fiesta.

But this year – a presidential election year when Americans are worried about the economy and feeling the pinch of growing energy pressures – some groups are using the event to share their points of view with as many people as possible.

Armed with his clipboard and dozens of voter registration forms, Chris Foster greeted some of the people who poured into Balloon Fiesta Park early Saturday. Fellow volunteers for Barack Obama’s Democratic presidential campaign were stationed at other entrances and at park-and-ride locations throughout the city, he said.

Their goal has been to register 30,000 voters in 30 days, and the deadline to register in New Mexico is Tuesday, he said.

“This campaign is very important to us,” Foster said. “This is a perfect thing here at the balloon fiesta.”

Across town, members of the international environmental watchdog Greenpeace geared up to launch their new Stop Global Warming, Save the Climate balloon. The balloon is colored like Earth to get people thinking about global warming, organizer Kristin Wheeler said.

“This is a historical and cultural event for the state of New Mexico,” she said of the fiesta, first held 36 years ago. “It’s a great way to elevate our message of stopping global warming to the thousands of people that will be here this week.”

Although fiesta officials acknowledged the political and environmental messages sneaking in, they have tried to keep politics off the launch field. They have strict rules about campaigning and handing out fliers, spokeswoman Kathie Leyendecker said.

“This is a huge event. It’s a spectator event. It’s a family event,” she said. “You’re pretty much looking up in the air and ooh-ing and aah-ing at all the beautiful balloons, and you don’t need someone tugging on your shoulder.”

Between 800,000 and 850,000 people are expected for the nine-day event. And Saturday was the perfect day for this year’s first mass ascension, as hundreds of balloons in all shapes and colors lifted off.

More than 600 balloons are registered for this year’s fiesta. It will also serve as the starting point for a cross-country gas balloon race that’s expected to start Monday.