Three days after a dramatic change in Republican candidates shook up the Massachusetts gubernatorial race, opposing campaigns and the Harvard political community are still regrouping.

On Tuesday, Republican Acting Gov. Jane M. Swift announced she would not seek election because of family commitments. Mitt Romney entered the race hours afterward. Romney, a former Republican senatorial candidate and 2002 Olympic organizer, is also a 1975 graduate of the Harvard Law and Business Schools.

Democratic candidate and former state senator Warren E. Tolman said he was surprised by the rapid turn of events.

“I was shocked. I was absolutely stunned,” Tolman said, “I always thought of [Swift] as a fighter.”

Tolman criticized Romney for his stance on education and a pro-choice position on abortion that he called “murky at best.”

“We may live only a couple miles apart, but we might as well be from different worlds,” Tolman said of Romney.

Jill E. Stein ’73, the Green Party gubernatorial candidate, expressed dismay at the Republican shake-up.

“It’s regrettable that Swift was pushed out,” Stein said. “Romney is a candidate with no positions and no record.”

Praising Swift for her support of Clean Elections legislation, Stein said there would be no meaningful Republican dialogue in the campaign because of her withdrawal.

At Harvard, student political activists reacted strongly to Romney’s entrance and Swift’s exit.

The Harvard Republican Club (HRC), which had initiated a slow-starting campaign behind Swift, has rallied around Romney, said President Brian C. Grech ’03.

“Romney is certainly the more celebrated character in this state,” Grech said. “I am not disappointed in [Swift’s] decision because she is yielding to another good Republican.”

Grech and Speakers Director Ernani J. Dearaujo ’03 said HRC is planning to mobilize the club’s membership, numbering about 200, to help the Cambridge-based Romney campaign.

They have also invited Romney to speak on campus.

Dearaujo said Romney’s entry into the race has “energized the party.” Dearaujo said he felt Romney’s chief advantages were his charisma—a trait he said was rare among Republicans—and his lack of connection to many of the controversies affecting the Swift administration.