A colleague passes on this assertion by Newt Gingrich about Rick Santorum: “He was a Big Labor Republican who consistently voted with the unions. Ironically, while he says that I’m not a real conservative, I had a 90 percent American Conservative Union rating. His is dramatically lower. So he actually was more liberal, according to the American Conservative Union, than I am.” Well, Santorum actually had an 88 percent rating so only in Gingrich’s mind is Santorum “dramatically” less conservative.

As for his assertion that Santorum “consistently voted with Big Labor,” there are certainly positions on which he disagreed with Big Labor. However, Santorum does have some problematic votes on union issues that he’ll need to explain.

In 1996 Santorum was one of just 14 Republican senators who voted against repealing the Davis-Bacon Act, which requires that government contract pay the prevailing wage. Conservatives have routinely targeted the act as adding billions to the federal budget and having a disparate impact on minority-owned contractors. In 1999, Santorum also voted against a measure to carve out an exemption for Davis-Bacon in federal disaster areas.

In July, 1996, Santorum was also one of only 14 Republicans who voted against right-to-work legislation (i.e. barring unions from requiring workers join the union).

Santorum explained his votes this way recently on Fox News Sunday:

“And you need to remember, I was from the state of Pennsylvania. State of Pennsylvania does not have a right to work law. The state legislature and our governor for a long time had rules in place that were inconsistent with right to work. And I wasn’t, as United States senator, representing the states of Pennsylvania going to go down and by federal vote change the law on the state. I believe the state has the right. If they want a union dues requirement, that the state should be able to do that. As a president, I have a very different point of view. I have already signed a letter and sent it to the national right to work that I would sign a national right to work bill because now, I’m no longer representing that state. And by the way, the same thing with respect to Davis-Bacon. My feeling was, again, representing that state, which has a large segment of contractors that work under those provisions that I would protect that right. Again, as a president, I would have a different view. But I did represent a constituency and one of the things I think is important is to listen and respect the rights of my state.”

That’s not a hugely compelling answer for conservatives who see right- to-work legislation as pro-jobs and pro-growth and who think Davis-Bacon is antithetical to budget control and equal opportunity.

And finally, Santorum cast a controversial vote in the House in 1993 when he was starting a campaign for the Senate that aligned him with Democrats and the Clinton administration. The Pittsburgh Post-Gazette reported: “Santorum broke ranks with fellow GOP members by backing a federal law to prohibit the hiring of permanent replacements for striking workers.”

These were understandable votes for a senator or senatorial candidate in Pennsylvania. But they do complicate the narrative in which he attacks Mitt Romney as a “Massachusetts moderate.” The Romney camp has yet to focus on this issue, but in many ways, given the recklessness of the president’s National Labor Relations Board appointees, it is a more timely issue than earmarks. Santorum would be wise to explain why he would take a different position as president on these issues, and simply admit an error. He’s already conceded his record is not “perfect.” If he does that, Romney, of all candidates, might find it hard to jump on him for a “flip-flop.”