The owner of a gift store across from the White House has been selling presidential merchandise since the '80s and has his own way of predicting who will win the election every four years -- button sales.
"Since 1988, I've been predicting who would win based on button sales that year," White House Gifts store owner Jim Warlick said. "We predicted it right every time except for Gore in 2000. And this time we got it wrong."
The gift shop staff had planned "to turn the store into the Hillary inauguration location," Warlick said. "We had no Trump inaugural [items] and we had no vendors that had anything."
Warlick says it took a few days to stock up on goods related to President-elect Donald Trump's inauguration, but now the store shelves are full.
Before election day, the most popular campaign items for sale at White House Gifts featured each candidate's slogan.
"The best-selling [Trump] item during the campaign was the red hat, 'Make America Great Again.' And then the 'Stronger Together' Hillary items were big sellers for her," he said.
But the candidate whose merchandise flew off the shelves more than any other's didn't make it past the Democratic primary. "Bernie [Sanders] items sold better all year than Trump or Hillary," Warwick said.
As the shop gears up for Trump's inauguration, Warlick is cognizant of the fact that his customers will be a mix of supporters and protesters of the incoming administration. He says they have merchandise for sale that caters to both groups.
Warlick estimates he has sold over 10 million pieces of political memorabilia over more than three decades. He first began selling inaugural merchandise in 1980 when President Ronald Reagan took office. He says sales of inauguration memorabilia really picked up during Bill Clinton's inauguration in 1993.
But, according to Warlick, no president to date can compete with the excitement surrounding Barack Obama's inauguration in 2009.
That inaugural, which drew an estimated 1.8 million people, "was unlike any other," Warlick said. "There were so many people here, the store was packed; they were down the street and around the corner. Anything with Obama's face on it would sell."
And he soon realized the president was not the only Obama in high demand. His customers started asking for items with the first lady's image, too.
"They liked Michelle better than they liked the president," Warlick said.
The popularity of Obama merchandise has continued over his two terms, so the store has created a "legacy line" of items that they plan to offer through the spring.
Learn more about Jim Warlick and the next chapter for the White House Gifts store in the video above.