Republican Gov. Chris Sununu announced Tuesday evening that he plans to seek a third term as governor, while two former Democratic rivals are mulling repeat bids of their own.

Sununu’s announcement came in a blog post on the website Medium Tuesday around 7 p.m.

“I truly appreciate the enthusiastic encouragement from so many that I run for the United States Senate,” Sununu’s blog post reads. “We all know that I would defeat Jeanne Shaheen, but others can too.”

Earlier that afternoon, The Sentinel inquired about whether he would pursue re-election or challenge Democrat U.S. Sen. Jeanne Shaheen for her seat in 2020.

Sununu’s campaign had no further comment after the blog post went live.

The Newfields Republican served on the N.H. Executive Council before being elected governor in 2016. He is the son of former New Hampshire governor and White House chief of staff John H. Sununu, and the brother of former U.S. senator John E. Sununu, who lost his seat to Shaheen in 2008.

On the Democratic side, former Portsmouth mayor Steve Marchand told The Sentinel Tuesday that he is considering running for governor for the third time. His most recent opponent and the party’s 2018 nominee, former state senator Molly Kelly of Harrisville, said last week that she’s “seriously considering” another run in 2020.

Marchand, who recently joined Democrat Andrew Yang’s 2020 presidential campaign as a senior adviser, said he thinks he can build off his support from the 2018 primary, where he lost to Kelly by 31 percentage points.

Amid turnout that nearly doubled the previous record for a New Hampshire Democratic primary in 2002, Marchand said that Kelly’s haul of more than 80,000 votes was part of a broader rebuke of President Donald Trump rather than enthusiasm about the governor’s race.

Marchand won 41,612 votes in 2018, up from the 18,331 he got in the 2016 primary against then-Executive Councilor Colin Van Ostern of Concord, who won the nomination with 37,696 votes before being defeated by Chris Sununu in the general election.

“We anticipated getting around 40,000 votes (in the 2018 primary), we identified them, and those people came out,” Marchand said. “But there were an extra 50,000 people with little to no history of voting in state primaries who came out and told us to our face, as they walked into the voting booth, that they didn’t even know who was running for governor, but that they wanted to make a statement about Donald Trump.”

Marchand added that he thought Kelly’s gender was a major factor for many new voters, which helped her expand her base of support beyond those who already knew her well from her decade in the state Senate.

“And that included maximizing the number of women that were nominees as part of making that powerful statement, which I completely appreciate and respect,” Marchand said. “The reality is that, for the most part, voters who supported me aren’t going anywhere.”

Kelly — who is the predecessor to N.H. Sen. Jay V. Kahn, D-Keene — served five terms representing much of Cheshire County in the state Senate from 2006 to 2016 after unseating Republican and former Senate president Thomas R. Eaton. She has also worked as an operative on myriad campaigns locally and statewide, emerging as a power player in New Hampshire politics.

This year, Kelly launched the political action committee Working for NH Families and Children, and said she thinks she can be most effective advocating for her signature issues, such as paid family leave, by remaining neutral in the presidential primary.

But she has served as a resource for Democratic campaigns traveling through the Monadnock Region, introducing candidates such as Beto O’Rourke and Kirsten Gillibrand during their visits to Keene State College.

“I do think that my role is really to make sure that all of the candidates feel welcome here,” Kelly said.

Marchand said campaigning for Yang, a former tech entrepreneur — whom Marchand introduced Tuesday night at a packed rally in Manhattan’s Washington Square Park — will not preclude him from another gubernatorial run.

After getting to know Yang over coffee in Manchester and snowmobiling in Coos County, Marchand said he decided to endorse the candidate and join the campaign as a paid senior adviser in early April. A major part of that decision, Marchand said, came from Yang’s blessing for Marchand to potentially pursue another gubernatorial run.

The third time could be the charm, Marchand said, because of Democratic enthusiasm in the Granite State. One promising indicator he pointed to was the 2018 vote totals of Congressional winners Ann M. Kuster and Chris Pappas, which, combined, exceeded Kelly’s statewide by about 40,000.

“That means that there are a lot of people who voted Democratic for everything except for governor,” Marchand said.

Despite Democrats taking back majorities in both chambers of the Legislature in 2018, key campaign promises, such as paid family leave, remain stalled under Sununu’s veto power.

Marchand said he believes that contrast could help him in 2020, where he said he would make the case to Democrats that a new, “more dynamic” nominee would be able to unseat Sununu, who currently enjoys 64 percent approval as the third most popular governor in the country, according to an April Morning Consult poll across all 50 states.

“We need to modernize our government,” Marchand said, “and we need to modernize our nominees a little bit.”

Jake Lahut can be reached at 352-1234, extension 1435, or Follow him on Twitter @JakeLahut.