Republicans listening to last night's primary debate might have been surprised to hear the question asked of former Massachusetts Gov. Mitt Romney by Fox News Channel's Juan Williams.

"Gov. Romney, Speaker Gingrich says your record of support for gun owners is weak," Williams said. "You signed the nation's first ban on assault weapons in Massachusetts and steeply increased fees on gun owners in that state, in fact by 400 percent. How can you convince gun owners that you will be an advocate for them as president?"

Romney answered that the legislation he signed "was crafted both by the pro-gun lobby and the anti-gun lobby. Massachusetts has some very restrictive rules and the pro-gun lobby said, 'You know what, this legislation is good for us, it includes provisions that we want that allows us, for instance, to cross roads with weapons when we're hunting that had not been previously allowed.' And so the pro-gun folks in our state, the Gun Owners Action League and others said, 'Look, we would like you to sign this legislation.' And the day when we announced our signing, we had both the pro-gun owners and anti-gun folks all together on the stage because it worked. We worked together. We found common ground."

Romney's overall gun record is more mixed that that. The Gun Owners Action League that Romney cites issued a February 2007 report  asserting that Romney made "some rather serious political missteps" early in his administration, though "relations dramatically improved," and eventually Romney became the most supportive governor of the group's issues since 1979.

But the larger issue for voters may have been: Romney raised fees on guns? He did? Where? How? When?

Indeed, largely due to the inability of Romney's competitors to run credible national campaigns that include voter registration and Get-Out-the-Vote, fundraising, event planning and- for the purposes of this discussion - opposition research, the governor has not had to answer many items about his record.

I'm not judging Gov. Romney as having done anything wrong in any of the below stories. Indeed, there will be readers who peruse the below and approve.

But these are aspects of Romney's record that conservative Republican primary voters are almost certainly unaware of, and in which they may be interested - certainly more so than the attacks that have so far been leveled, such as the populist digs at Romney's time at Bain Capital, which have in many ways solidified support for the front-runner among some business conservatives.

For whatever reason - likely because of the anemic opposition research efforts in Romney's rivals' struggling campaigns - these aspects of the Romney have not been raised.

Here are the Top Three Missed Opportunities for Conservative Attacks:

1. Free Cars for Welfare Recipients?

In 2006, Romney started a program to provide welfare recipients without access to public transportation with free cars. The idea was to provide them with a way to get to work so they could eventually get off welfare.

The cars were donated by charities, while Massachusetts taxpayers funded - as the Boston Herald reported in 2009 - "repairs, registration, insurance, excise tax, the title and AAA membership for one year."

Romney's Department of Transitional Assistance started the program, officially called "Transportation Support," and nicknamed "Welfare Wheels" by the Boston Herald.

You can read more about the program HERE.

The program was discontinued in 2009.

"I don't care who started it," said then-state senator (now U.S. Senator) Scott Brown, a Republican. "In this day and age, it's not appropriate. I mean, we're paying for Triple A? You've got to be kidding me."

"We can't be giving out freebies," Democratic state Sen. Steven Baddour said. "At a time when we're cutting programs across the spectrum and working families are struggling to pay the bills, this program is just too rich for this budget."

In 2011, Romney for President spokeswoman Gail Gitcho defended the program to the Herald, saying "over 80 percent of participants have moved off of welfare." In 2006, the program cost Massachusetts taxpayers $400,000; Gitcho claimed over three years the program saved the state almost $1 million in welfare payments.

2. Early Release for Prisoners Serving 'Life' Sentences Peaked Under Romney

Romney and former Pennsylvania Sen. Rick Santorum got into a back-and-forth last night about voting rights for felons. Santorum brought up the issue, because a Romney-supporting super PAC is depicting him as supporting prisoners getting voting rights, in his view, as opposed to giving rights to those who have served their time, earned parole, and paid their debt to society.

While Santorum was hoping to show that Romney was a hypocrite - the law in Massachusetts while Romney was governor was more permissive than what Santorum had voted for - the debate allowed Romney to say, "I don't think people who have committed violent crimes should be allowed to vote again. That's my own view."

What Santorum may or may not know is that, according to a 2011 analysis by the Boston Globe, "over the past 20 years, the percentage of inmates paroled while serving a life sentence … peaked in 2004? - when Romney was governor - "and when all seven members of the state Parole Board had been appointed or reappointed by Republican governors."

And that, according to the Boston Herald in 2008, "Some 118 killers and rapists were sprung early from prison under former Gov. Mitt Romney's watch … allowed to walk out the gates by the Department of Correction by claiming so-called 'good time' that in some cases substantially reduced their sentences."

That's likely more of a concern to Republican primary voters than those ex-cons' suffrage.

The Romney campaign has pointed out that the governor's first two nominees to the Parole Board were rejected by The Governor's Council as too hard-line. A majority of the appointees on the Parole Board were not Romney's until late 2005. As governor, Romney did not issue a single commutation or pardon, and he tried, to no avail, to reinstate the death penalty.

3. Free Abortions

"On every piece of legislation, I came down on the side of life," Romney said at the Family Research Council's Values Voters Summit in 2007.

That's a matter of interpretation.

For instance, Romney's Massachusetts health care reform law created an 11-member "Health Care Connector Board" that would ensure affordable pricing for various health insurance plans. Romney appointed actuary Bruce Butler, CEO of Associated Industries of Massachusetts Rick Lord, and economist Jonathan Gruber. Four administration officials from Romney's cabinet were also appointed to the board, per the law: his Secretary of the Executive Office for Administration and Finance; the Medicaid Director in the Commonwealth of Massachusetts; the Commissioner of Insurance; and the Executive Director of the Group Insurance Commission.

The law also allowed the governor to appoint the executive director of the Connector Authority, and Romney picked senior vice president for policy development at Tufts Associated Health Plan Jon Kingsdale.

Kingsdale wrote a memo to the Connector Authority recommending that for abortions, insurance companies require co-pays between $0 and $100, depending on income level. In September 2006, that was approved by the Connector Authority. Every health care plan offered to low-income Massachusetts residents covers abortion.

Want to see for yourself? Go to this archived page from the 2006 Connector Authority,  and download the "Commonwealth Care Frequently Asked Questions" at the bottom left side of the page.

At the 2009 Value Voters Summit, Mike Huckabee said, "The only thing inexpensive about Massachusetts' health care bill is that there you can get a $50 abortion."

The Romney campaign's response is to assert that "The Connector Authority" is independent and separate from the governor's office. That's technically true, but the majority of members of the Connector Authority were appointed by the governor one way or another.

(UPDATE: The Weekly Standard's John McCormack points out that Gingrich has indeed made the abortion argument - just maybe not effectively. So I am adding the link and I changed the title to "effectively," though I haven't seen the other two items mentioned above even uttered by Romney's rivals.)

-Jake Tapper