Charles D. Baker ’79, a Massachusetts politician and businessman and the Republican gubernatorial nominee four years ago, will announce Wednesday that he plans to run for governor of Massachusetts next year, the Boston Globe reported Tuesday.

Baker, former CEO of Harvard Pilgrim Health Care, ran an unsuccessful campaign against Governor Deval L. Patrick ’78 four years ago, losing by a margin of 6.4 percent.

After former Massachusetts senator Scott Brown refused to enter the gubernatorial race in late August, Baker emerged as the likely Republican contender for the nomination. Baker, like Brown, has been described as fiscally conservative but socially liberal, an ideological combination more reflective of the traditionally Democratic-leaning state’s preferences.

“Charlie Baker knows that if he were to run a race that would mimic that national Republican Party, he would lose,” Democratic political consultant Dan Payne said. “He has to look and sound moderate to attract the votes of conservative Democrats and moderates.”

Baker’s progressive stances on social issues have drawn supporters among moderate voters, although Payne has also noted that Baker has avoided controversial topics that might force him to take conservative stances unpopular among many Massachusetts voters.

“He has not been outspoken on issues that Republicans have been losing on, like abortion and same-sex marriage or even the death penalty,” Payne said.

Baker’s ability to straddle the divide between fiscally conservative and socially liberal issues has placed him atop pundits' lists of possible Republican nominees for the race.

“Ever since the last time he ran for governor, the assumption has been that he will run again,” Payne said. “His efforts to get into the race will come as no surprise to Republicans or Democrats.”

Payne suspects that no other candidates will challenge Baker in the Republican primary.

The last gubernatorial race focused on the issues of employment and the economy. Baker pledged to prevent tax hikes and lambasted incumbent Patrick for lackluster attempts to jump start the stagnating economy. However, facing competition from a moderate independent candidate in the race, Baker was forced to adopt more stringent right-leaning views, a mistake that, according to Payne, Baker is unlikely to make again.

Additionally, the choice to declare his candidacy over a year before the election should give Baker more time to line his campaign coffers, making him an even more competitive opponent against the Democrats.

“Baker will be hard to beat,” Payne said.

Should he enter the race, Baker would join a crowded field that already includes three Harvard graduates vying for the governorship. Steven Grossman (HBS ’69), Donald M. Berwick ’68, a health care policy lecturer at Harvard Medical School, and Juliette N. Kayyem ’91, a lecturer in public policy at Harvard Kennedy School, have already announced their intention to run next fall.

Patrick, also a Harvard graduate, is eligible to run for reelection but has stated that he will not seek a third term.

­—Staff writer Laura K. Reston can be reached at laura.reston@thecrimson.com. Follow her on Twitter @laurareston.