DENVER -- As polls show Democrat Sen. Barack Obama leading in his race with Republican Sen. John McCain for president of the United States, more and more Americans are arming themselves.

Gun sales are up nationwide and in Colorado.

"Probably an increase of 25 percent," said Richard Taylor, manager of the Firing Line in Aurora.

Time and again, Taylor said customers, especially first-time buyers, say they're afraid an Obama White House would mean more gun control.

"If Barack Obama gets in, people are concerned they might not be able to purchase certain types of firearms. So that has been driving a number of the sales," Taylor said.

"The upcoming election, I guess you could say, is part of it too because these guns may not be accessible to the civilian population," said Nicki Cook, a math tutor buying an AR-15.

The graduate student at Regis University said she will share the military-style rifle with her boyfriend for "fun," not protection.

Raised around guns and already an owner of a handed-down handgun, Cook said politics did play a role in the timing of her purchase.

"Not nervous but, just, do it while I can, I guess," Cook said.

Many so called "assault rifles" were banned for 10 years under the Brady Bill, passed in 1994. The law was allowed to sunset and expire in September 2004. It prohibited the sale of high-capacity rifles with bayonets, collapsible stocks and magazines with more than 10 rounds of ammunition.

The Colorado Bureau of Investigation saw a nearly 11 percent increase in the number of background checks processed in September of this year versus September 2007.

A spokesman said they routinely do see increases in the fall, largely due to hunters getting ready for the season.

"I just think a lot of people are concerned about their Second Amendment rights," Taylor said.

A spokesman for the Obama campaign, Iraq war veteran and former Glendale mayor Joe Rice, said Obama supports the Second Amendment. He said people in Colorado would not see a change in gun in laws if the Democratic candidate is elected president.