Non-stop ads and robocalls: welcome to America's costliest election

Wendy Burke has had enough. Campaign advertisements bombard her favorite TV shows. Dozens of election pamphlets fill her mailbox. Every day, she gets several political calls on her cell phone and more on her landline. Strangers knock at her door seeking her vote.

"It's ridiculous," Burke, 47, said outside a shopping center in Palmdale, California. "I've had to block my calls."

Welcome to the most expensive race in the hard-fought battle between Republicans and Democrats for control of the U.S. House of Representatives, which will be decided in Tuesday's elections.

The blizzard of spending in California's 25th district, a region stretching north and east of Los Angeles into the high desert of the Antelope Valley, stands out even during the most expensive congressional elections in U.S. history.

Most of the money is funneled into non-stop advertising - on TV, radio, social media, yard signs, automated robocalls to cell phones and land lines, bumper stickers and a deluge of pamphlets stuffed into mailboxes.