In the Republican presidential primary, “mandate” has become a four-letter word. No one wants to get caught on the wrong side of President Obama’s health reform law, which includes an unpopular (and some say unconstitutional) requirement that Americans purchase health insurance. But mandates don’t seem to be disappearing: Candidate after candidate has tangled with prior support for requiring individuals or insurance companies to do certain things. As Karl Rove put it on Fox News this morning, “The ironic thing is we now have the two front-runners — Gingrich, the new contender, having favored an individual mandate for the entire country — and Mitt Romney, the former or maybe current front-runner nationally, having supported a mandate for his state of Massachusetts.”

Here’s a guide to what we know, so far, about the health care mandates that Republican presidential candidates have previously supported.

Mitt Romney — As Massachusetts governor, Romney signed the state’s 2006 health reform package that required Massachusetts residents to purchase insurance coverage or pay a penalty. The fine for not carrying health insurance has increased each year and, in 2011, will be as high as $1,200. In an interview with Sean Hannity in September, Romney described the mandate as a “conservative idea to say, you know what? People have a responsibility for caring for themselves if they can.” He has also criticized the federal mandate as “a government takeover of health care,” arguing that such decisions about health care mandates ought to be left to the states.

Jon Huntsman — Shortly after Massachusetts passed health reform, then-Utah Gov. Jon Huntsman began exploring a similar plan in his own state. When asked by a local reporter whether he would support a mandate in 2007, Huntsman said, “I’m comfortable with a requirement, call it what you want.” Huntsman was comfortable with the requirement, but did not pursue it: The health reforms he signed into law later that year did not require Utah citizens to carry coverage.

Rick Perry — As Texas governor, Rick Perry signed a controversial law requiring HPV vaccines for sixth-grade girls in 2007. It was the first such mandate in the nation and was overturned by the Texas State Legislature the following year. Less noticed, Perry also signed a 2009 law that requires health insurance companies to pay for CT scans and ultrasounds that could detect heart diseases. That law, which remains on the books, has been criticized as increasing health care spending without proven health outcomes.

Newt Gingrich — As Huffington Post’s Sam Stein detailed in a lengthy article, Newt Gingrich has repeatedly supported the mandated purchase of health insurance (which, as Ezra has pointed out, wasn’t unusual for Republicans in the 1990s). “I agree that all of us have a responsibility to help pay for health care,” he told “Meet the Press” earlier this year.

But Gingrich has also backed away from that position, releasing a video shortly after the “Meet the Press” interview declaring “I am completely opposed to the Obamacare mandate on individuals.” Gingrich may not, however, speak for his consulting firm: As Mother Jones’s David Corn reported earlier this week, the Gingrich Group currently supports a health reform plan that would require the purchase of health insurance.