Donald Trump Jr. was drumming up support of U.S. Congress Republican candidate Greg Gianforte at an energized crowd of hundreds Friday afternoon in Hamilton.

The President's son was on stage at the Event Center of the Ravalli County Fairgrounds with Gianforte and U.S. Senator Steve Daines. Trump was the featured speaker, talking about how Gianforte would work well with the Trump agenda in Washington. He praised his father's initial weeks in office.

Trump also urged the crowd to vote and get their friends to vote in the special Montana election May 25. The election is gaining national attention.

Trump noted his friendship with Gianforte. He spoke glowingly of the Montana lifestyle, relating experiences he has had in the Montana outdoors.

Senator Daines also spoke in support of Gianforte, saying they had been friends for 20 years. Gianforte, when he addressed the Hamilton rally, noted the differences between himself and Democratic candidate Rob Quist.

This is Gianforte's second visit to Hamilton in less than a week. The first appearance was for the Advancing Conservatism meeting Monday, April 17. This engagement was part of a four-city tour with stops in Kalispell, Hamilton, Billings on Friday, wrapping up in Bozeman Saturday.

Trump, Gianforte and Daines. (Steve Fullerton, Townsquare Media)

The special election in May is to select a replacement for Ryan Zinke in the U.S. House of Representatives. Zinke has joined the Trump Cabinet as Secretary of the Interior. Republican Gianforte, Democrat Quist and Libertarian Mark Wicks are on the special ballot.

Protesters lined the street outside the Ravalli County Fairgrounds, chanting "Montana's not for sale."

Protesters at Gianforte rally. (Steve Fullerton, Townsquare Media)