Governor Larry Hogan, flanked by House speaker Michael E. Busch (L) and Lt. Gov. Boyd Rutherford at the start of the 2017 legislative session. (Linda Davidson/The Washington Post)

Maryland Gov. Larry Hogan (R) is entering his third year in office with more than $5 million available for his 2018 reelection campaign, beefing up his defenses against Democrats eager to reclaim the governor’s mansion in what’s been a traditionally deep-blue state.

Hogan and Lt. Gov. Boyd Rutherford raised about $4.5 million in their second year in office, according to 2016 campaign finance disclosures filed Thursday. That’s more than double the $1.7 million Hogan raised in his first year.

Hogan’s predecessor, Martin O’Malley (D), reported having a little more than $1.7 million available two years into his first term. The state’s last Republican governor, Bob Ehrlich, also had about $5 million halfway into his term, and lost to O’Malley in 2006.

Hogan, whose approval ratings have soared above 70 percent, relied on public funding in his successful 2014 campaign against then-Lt. Gov. Anthony G. Brown (D). Donors flooded Hogan and the state Republican Party with contributions in the months after his victory.

In 2016, individuals donated about 60 percent of Hogan’s campaign cash, with organizations and businesses making up much of the rest. About 14 percent of his haul came from donations of $250 or less.

In a memo obtained by The Washington Post, a consultant told Hogan advisers that the campaign was far exceeding its internal goals and fundraising by previous governors.

“With our strong fundraising network and foundation, and the governor’s record high approval ratings, potential challengers will have a difficult time getting any traction before the election year,” the memo says.

The early hauls are a sliver of spending in governor’s races, which have topped $20 million. But potential Democratic challengers have a lot of catching up to do to mount a serious race.

— Baltimore County Executive Kevin Kamenetz, who is cannot seek re-election in 2018 because of term limits and has said he’s considering a gubernatorial run, led the pack of potential opponents with $1.6 million after raising about $460,000 last year. He’s been aided by former O’Malley fundraiser Colleen Martin-Lauer.

— Prince George’s County Executive Rushern Baker, also facing term limits, reported about $250,000 cash on-hand. He spent almost as much as he raised in 2016.

— Del. Maggie L. McIntosh (Baltimore), considering runs for state comptroller or governor, had $125,000.

— U.S. Rep. John Delaney, who has been a loud critic of Hogan, can tap only $6,000 from his federal campaign account for a state run, but the wealthy former financier has largely self-financed his political races.

— Doug Gansler, a former attorney general who unsucessfully sought the Democratic nomination for governor in 2014, reported no fundraising and just $32,000 available, but spent money on several political meetings and dinners in recent weeks. He has said he’s been asked to run against Hogan, but has been noncommital about attempting a political comeback.

Ovetta Wiggins contributed to this report.