Maryland Del. Christian J. Miele (R) speaks as Gov. Larry Hogan (R) and Miele’s wife listen at the lawmaker’s campaign kickoff event on June 8. (Josh Hicks/The Washington Post)

Maryland Gov. Larry Hogan (R) has made his first endorsement of the 2018 election, backing a young Baltimore County lawmaker for one of six state Senate seats his party is targeting in an effort to break the Democratic supermajority in that chamber.

Hogan announced his support for Del. Christian J. Miele (R) at a campaign kickoff event Thursday night, helping the candidate raise at least $34,000 to challenge Sen. Katherine A. Klausmeier (D-Baltimore County) in the eastern part of the county. Miele’s campaign had about $45,000 cash on hand before the rally.

“We’re just getting started on our effort to turn Maryland around and change Maryland for the better, but I can’t do it without good members of the Senate like the gentleman we’re here to support,” the popular first-term governor said. “There’s no question in my mind that he will do an excellent job as your next senator.”

Hogan also used the occasion to publicly reveal the sex of the baby that the 36-year-old lawmaker and his wife are expecting later this year, tearing open a bag of blue balloons to indicate that the child will be a boy.

Miele, one of two sons of an Italian American father, said he’s happy someone will be able to carry on his family’s name. “Miele lives on!” he yelled to supporters.

Hogan is hoping Miele can take over a seat in a critical battleground district, potentially expanding the governor’s influence over negotiations in the legislature, where Democrats hold veto-proof majorities in both chambers.

Klausmeier’s district is part of the state Republican Party’s “Drive for Five,” an effort to flip enough Senate seats next year to deny Democrats the 29 votes they need in that chamber to override vetoes.

“This is not the first time they’ve targeted me,” she said after visiting an elementary school with other members of her district’s delegation on Friday. “I just have to keep doing what I do. I try to be in as many places as I can be and help as many people as I can.”

The senator, a four-term incumbent serving as her chamber’s deputy majority leader, won reelection in 2014 with 61 percent of the vote. She also served two terms in the House of Delegates.

But Hogan won 68 percent in her district, and his statewide approval rating was 65 percent in March. Miele is banking in part on being able to ride those coattails.

The first-term lawmaker, who serves on the House Health and Government Operations Committee, said his focus in the Senate would be helping small businesses, providing tax relief for seniors, bolstering public safety, securing state funding for new schools in the county and ending partisan gerrymandering of the state’s voting map.

“I’m firmly committed to being one of you and never being one of them,” he said, referring to the political establishment in Annapolis.

More than 300 people attended the event at a small reception hall in Nottingham, with most paying $50 for general admission and between $100 and $1,000 for special tickets.

Angie Thuman, a 38-year-old Parkville resident who does administrative work for a bank, said Miele helped secure state funding to renovate a park in her neighborhood. She and her husband, who were among the constituents Miele invited to attend the kickoff at no charge, want him to push for a new high school in the district.

“He came into our community and literally went door to door meeting people,” she said. “He won me over with his personality and his willingness just to do for people. He’s a listener, and then he goes out and makes it happen.”

Republican leaders see a potential star in Miele, whose pastor helped introduce him at the event. Many describe him as a moderate lawmaker who is willing to work across the aisle with Democrats — as opposed to more hard-line Republicans such as Del. Patrick L. McDonough (R-Baltimore County).

“He’s the kind of thing we’re looking for in a candidate as Republicans,” said Tim Robinson, president of the Reagan Republican Club of Baltimore County. “We have to speak to the majority of Maryland voters, who are socially moderate and fiscally conservative.”

A previous version of this article incorrectly stated that Del. Christian J. Miele is the only son of an Italian American father. He is one of two sons.