Republican Ande Smith clung to a 2 percentage-point lead over his primary opponent, Mark Holbrook, Wednesday morning in a close contest to challenge incumbent Democratic U.S. Rep. Chellie Pingree in November.

The race remained too close to call at 9 a.m., with Smith leading Holbrook by just 228 votes out of 20,472 votes tallied in Maine’s 1st Congressional District Republican primary, with 96 percent of precincts reporting. Most of the outstanding precincts were small towns and island communities.

Neither candidate had declared victory or conceded as of 9 a.m. Wednesday.

“It is still a lot closer than we would have liked, but we are cautiously optimistic,” Smith, of North Yarmouth, said late Tuesday night.

Smith, 51, is a former nuclear engineer officer aboard Navy submarines and is currently a captain in the Navy Reserve. Smith is also an attorney who runs Deer Brook Consulting, a firm that focuses on cybersecurity and technology.

Holbrook, of Brunswick, is a professional counselor who previously worked as a police officer for 12 years, as well as a lobsterman, a commercial diver and an instructor. In his private counseling practice, Holbrook works with veterans, law enforcement personnel and families. He also has worked in crisis response, suicide prevention and hostage negotiations.

Holbrook described himself as “the only conservative choice in the race.”

The two men have run a lively campaign in a district that has elected a Republican for only one two-year term since 1987.

Although Smith has never held elected office before, he currently serves on the Maine State Board of Education and until recently was a member of the Maine Charter School Commission.

During his campaign, Smith argued that both his 30-year Navy career as well as his experience in the private sector and running his own business provided him with the “tools, knowledge and temperament” to lead in Congress.

Smith has highlighted the need to require a balanced federal budget, to decrease the national debt and to rein in the “unrestrained growth in regulations” stifling business development. He supports repealing the Affordable Care Act, strengthening U.S. border security and taking a stronger stance against China, Russia, Iran and the Islamic State.

He had outpaced Holbrook in fundraising, receiving more than $130,000 in donations from individuals through the end of May, compared with $24,600 for his primary opponent.

Holbrook sought to differentiate himself from Smith with his hard-right stances on issues such as abortion, immigration and the Second Amendment. Holbrook argued that illegal immigration is one of the major problems facing the U.S. and supported presidential candidate Donald Trump’s call to build a wall along the country’s southern border with Mexico.

He pledged to work closely with the LePage administration as well as Rep. Bruce Poliquin, R-2nd District, to bring larger employers to Maine.

Either man likely would face an uphill climb to defeat Pingree given the name recognition and substantial fundraising abilities enjoyed by congressional incumbents. The two candidates met several times for televised debates. The race took a negative turn in recent weeks.

Smith’s campaign accused Holbrook of using his website to make personal attacks against Smith and his family. And at the end of a recent television debate on WCSH, Holbrook refused to shake Smith’s outstretched hand. Holbrook, meanwhile, has sought to portray Smith as an “establishment candidate” and recently described him as “a slick-talking lawyer who always leaves wiggle room.”