- "Show up. Be part of it," Sean Duffy said
- More than 40 lawmakers are boycotting the inauguration
"I'm disappointed, you know, that all these Democrats are saying they are going to stay home," he told CNN's Chris Cuomo on "New Day." "It's like I was a little kid and I'm used to getting a juice box and a trophy no matter whether I win or I lose."
"Listen, Democrats lost. Donald Trump won. You might not like him and you may not agree with his agenda - just like we didn't agree with President Obama's agenda. But show up," the Wisconsin Republican continued. "Be part of the process."
He added later, "Put your big boy pants on and let's start working together."
Dozens of Democratic lawmakers are boycotting President-elect Donald Trump's inauguration, particularly after revelations of the intelligence community's assertion that Russia's meddled in the 2016 election and Trump's rebuke of civil rights icon John Lewis on Saturday.
Some members have said they will be protesting in Washington and in their districts instead.
Duffy, who supported Trump in the election, said the Democrats are setting a bad precedent for how future lawmakers should respond when a presidential candidate they don't support is elected.
"What happens with the next Democrat Presidential-elect that goes through their nomination, are Republicans now supposed to say that we're going to stay home? That these events become partisan in nature," Duffy asked. "That's bad for the country."