Washington CNN  — 

Rand Paul’s campaign is crowdsourcing ideas for an upcoming television ad, calling on Tuesday for “liberty-loving filmmakers” to submit entries that could air to support the Kentucky senator’s White House bid.

“This is the first time this has ever been done on the presidential level,” said Vincent Harris, the campaign’s chief digital strategist.

The campaign has also crowd-sourced designs for the campaign’s bumper stickers and T-shirts. Harris credits the campaign’s grassroots supporters, suggesting the contest is an alternative to making phone calls or knocking on doors.

“Not every campaign on both sides of the aisle can do this successfully,” Harris said.

The contest specifies that to be considered, ads must be in line with one of the campaign’s themes: Term limits, “Defeat the Washington Machine,” “Ending the IRS/Rand Paul’s 14.5% Fair and Flat Tax,” or “Right to Privacy/Ending Illegal NSA Spying.”

Harris said the winning ad will be promoted in Iowa and will run before the 2016 Iowa caucuses. After submissions close, the campaign will select standout videos and will let the public vote for the winner, who will not be paid for the spot.

According to the contest’s official rules, all entries must be submitted by 11:59 p.m. ET on Oct. 31.