BOSTON (AP) — Republican Gov. Charlie Baker hasn't officially declared his 2018 re-election campaign yet, but that hasn't stopped him from raising money at a ferocious clip.

As of the beginning of October, Baker reported having more than $6.5 million in cash in his campaign account.

By contrast, former Democratic Gov. Deval Patrick had just $490,000 in his re-election campaign account at the same point during his first term in office, according to an Associated Press review of campaign finance records.

Former Republican Gov. Mitt Romney had a tenth of what Baker has in his account, about $640,000, at the same point during his first and only term. Romney opted not to seek re-election to focus on his presidential ambitions.

Baker's advantage over his Democratic challengers doesn't stop there.

His presumed running mate should he seek re-election in 2018 as expected — his Lt. Gov. Karyn Polito — has another $3 million in her campaign, giving the GOP team more than $9.5 million in cash on hand with the election more than a year off.

The Republican State Committee also has reported having more than $400,000 in its account as of the beginning of October.

In addition to a massive campaign war chest, Baker remains popular with voters in Massachusetts, another hurdle facing Democrats hoping to limit him to a single term.

Those Democrats are nowhere close to Baker on the fundraising front.

Jay Gonzalez, a top budget official under Patrick, had $50,000 in his account as of Oct. 1. Newton Mayor Setti Warren had $36,000. Environmental activist Robert Massie — another Democrat running for governor — had just $18,000.

The Democratic State Committee has just over $200,000 in its account, about half of what the Republican State Committee has.

Even one of the top Democrats in state government, Attorney General Maura Healey, trails Baker by almost a 6-1 deficit. Healey had just $1.2 million her campaign account, the most of any Democratic constitutional officer in Massachusetts.

Healey, now in her first term, repeatedly has said she has no intention of trying to challenge Baker next year.

Baker is benefiting in part from a change in state campaign finance laws signed by Patrick in 2014 that doubled the maximum annual donation from $500 to $1,000. The change took effect just as Baker became governor.

Of the more than $8.4 million Baker has raised since taking office in January, 2015, about half — or more than $4.2 million — came in the form of single $1,000 donations, according to the AP review of reports filed by the candidates with the state Office of Campaign and Political Finance.

About $1 out of every $10 Baker has raised since taking office, or $881,000, came from out-of-state donors.

David Drummond, finance director for Baker's political committee said the fundraising reflects the faith that supporters have in the governor's priorities in office.

"Gov. Baker and Lt. Gov. Polito have secured tax breaks for working families, increased funding for public education while stopping wasteful spending, so it's no surprise that they continue to receive support from across Massachusetts," Drummond said in a statement. "Their bipartisan approach to getting things done is resonating and we are grateful for the support."