"Businesses that don't provide health insurance will be taxed $295 a head," she warned in her 2006 USA Today op-ed.
Romney used his line-item veto power to delete the employer assessment from the Massachusetts health care legislation, but the Democratic-controlled legislature overrode his veto and it became law.
Pipes also objects to the individual mandate in Romney's state plan because she believes the young and healthy would rather pay a fine than buy an expensive policy. In her Boston Globe op-ed, Pipes wrote that the $216 fine imposed by Massachusetts on individuals who do not purchase health insurance would be "more attractive than the premiums."
The Romney campaign responded to Pipes' criticism by pointing to a 2007 state report showing that the average uninsured individual in Massachusetts -- whom the state calculates to be 37 years-old -- can get private health insurance, including coverage for prescription drugs, for somewhere between $184 and $279 per month, depending on the region of the state.
If purchased on a pretax basis through the plans that employers with 11 or more full-time employees are required to make available, the average net cost of insurance in an inexpensive region is reduced to $115 for a single individual earning $50,000 per year, according to the 2007 state report.
Despite his support for an individual mandate at the state level, Romney will not propose that an individual mandate be prescribed at the federal level.
"There are some states that could choose an individual [mandate] approach in order to control costs, and others that might not," said Madden.
Giuliani's plan and the plan Romney is expected to unveil at some point over the next two months are on the same page when it comes to correcting the tax bias against insurance that is individually purchased, rather than that which is employer purchased.
The two men differ, however, on whether the United States would be better served by creating a national health-insurance market.
"Rather than force people to buy plans approved by their state," Giuliani would "allow people to shop anywhere," Pipes wrote in The Wall Street Journal in June.
Pipes told ABC News that allowing for the purchase of health insurance policies across state lines would make less-expensive catastrophic plans available to more people.
"Psychiatric treatment and alcoholic treatment and in vitro fertilization all add to the cost," she said.
The downside of buying insurance across state lines is that many of the treatments required under various state regulations are popular and medically important, a key reason why efforts to pursue such a reform failed last year when attempted by the Republican Congress.
Citing statistics compiled by the National Conference of State Legislatures, the Democratic National Committee argued this week that the state regulations which would be undermined include direct access to OB/GYNs in 44 states, colorectal cancer screening in 23 states and mental health parity in 45 states.
When asked about Giuliani's call for a national health-insurance market, Romney spokesman Madden told ABC News: "I don't expect an initiative like that to be part of the approach" Romney unveils. Coming out against a national health-insurance market would inoculate Romney against the Democratic charge (already facing Giuliani) that such a plan would have the effect of "gutting" state health-insurance regulations.