MANCHESTER, N.H. -- An assertive Mitt Romney has emerged in the Republican presidential race.
For months the former Massachusetts governor has shown little willingness to assail his GOP competitors, staying above the fray and focusing all his criticism on President Barack Obama.
But in one night, Romney became the most prominent aggressor in a growing effort by the GOP field to derail front-runner Rick Perry. And in doing so, Romney may have started to ease concern within the GOP establishment over the strength of his candidacy.
"Those doubts were erased," Steve Duprey, a Republican National Committee member from New Hampshire, who is unaligned in the race, said Tuesday, a day after a Republican presidential debate in Tampa, where Romney tested out his on-the-attack approach.
"In a dominant fashion, he showed he could take and fend off Governor Perry's blows and at the same time deliver sound, hard-hitting policy criticisms of Governor Perry. After that debate, Romney looked strong. Perry looked dazed," Duprey said.
It's the beginning of a new phase in Romney's campaign; aides said the time has come to contrast Romney's record with those of his opponents.
, and they expect Romney will keep the pressure on Perry, specifically.
Criticism on such issues as immigration, Social Security and jobs is expected on the campaign trail and in another debate next week.
The shift reflects a growing sense of urgency in Romney's campaign and others that Perry must be knocked down before he becomes too strong and runs away with the nomination.
For months, Romney sat atop public opinion polls across the nation and in early primary states, seemingly the top preference of Republican voters who denied him their party's presidential nomination in 2008. He spent much of the year ignoring darts from his rivals.
Then Perry entered the race a month ago and immediately shot to the top of polls. And, within days, Romney started drawing contrasts with Perry without naming him, highlighting his own business background while generally noting that there also were "career politicians" in the race, an obvious reference to Perry.
Romney showed signs of a willingness to go after Perry in their first debate together last week, but he shifted his strategy completely during the opening minutes of Monday's debate as the candidates sparred over Social Security, the program Perry has repeatedly described as a "Ponzi scheme."