Mitt Romney has had a lot to say about immigration over the past few days, but what he has said adds up to a giant question mark. Rarely has a presidential candidate had as many opportunities to clarify or recalibrate his position on a vital issue, and rarely has a candidate passed up those opportunities as consistently as the former governor.

It’s not that Romney has mostly avoided talking about immigration during the campaign. When it has been in his political interest, he has been more than happy to state his views. He took on the issue repeatedly during the Republican primaries, using it as a cudgel to attack Texas Gov. Rick Perry and former House speaker Newt Gingrich (Ga.) and at a critical moment in his fight against former senator Rick Santorum (Pa.).

When Perry appeared to be a threat, Romney was eager to blast the governor’s support of a long-standing Texas law that allows residents who are the children of illegal immigrants to pay in-state tuition at Texas colleges and universities.

“It makes no sense,” Romney said.

When Gingrich outlined a conciliatory approach to dealing with undocumented immigrants who have been in the United States for a quarter-century or longer — a policy that would have provided legal status but not a path to citizenship — Romney attacked him, saying that any such policy would be a magnet for more illegal immigrants. He called Gingrich’s idea “a form of amnesty.”

When Romney debated in Arizona and desperately needed to defeat Santorum there and in Michigan, he appeared to say that Arizona’s hard-line approach to immigration — including the law that the Supreme Court mostly struck down on Tuesday — was a model for the nation. (The court upheld the legislation’s most contested provision, which requires law enforcement officials to check the immigration status of people they detain and suspect to be illegal immigrants.)

Called on it by reporters, his campaign said at the time that, no, Romney didn’t say the Arizona law before the courts was a model for the nation. They said he was talking about the state’s e-verify law for businesses dealing with applicants who might lack documentation, campaign officials said. Exactly what the candidate thought of the strict anti-immigration law was left to the imagination, though he did win the endorsement of Arizona Gov. Jan Brewer (R) before the primary.

Romney has long opposed a comprehensive immigration reform policy that would include a path to citizenship for the roughly 12 million undocumented immigrants living in the United States other than making them return to their native countries and get in line. During one debate, he famously described this policy as “self-deportation.” He has been consistent on this through both of his campaigns for the White House.

That brings us to the past two weeks, when the former governor went fuzzy in public on immigration. It began when President Obama, in a move that was as political as it was substantive, issued an order that halted the deportation of illegal immigrants who came to the United States as children if they met certain criteria.

Catching Romney off guard, the president put his rival in a tough spot, because Romney had promised earlier to veto the Dream Act, which was designed to do what Obama had just ordered. Romney could hardly have been less forthcoming when he responded to a series of questions about whether he supported the new policy.

All he was willing to say was that he opposed the process by which the president acted. Pressed to explain his position by Bob Schieffer on CBS’s “Face the Nation,” Romney ducked the question. One exchange went as follows:

Schieffer: “But would you repeal this?”

Romney: “Well, it would be overtaken by events, if you will. . . .”

By that, Romney said he meant that he would replace the president’s temporary policy with his own permanent policy. The contents of that policy remain unclear. Romney has said nothing to reverse his opposition to the Dream Act. He offered little encouragement to earlier efforts by Sen. Marco Rubio (R-Fla.) to find compromise legislation.

Romney had another chance to clarify his views on immigration when he spoke at the meeting of the National Association of Latino Elected and Appointed Officials in Florida on Thursday. There, he laid out a solid critique of Obama for not fulfilling his 2008 campaign promise to enact comprehensive immigration reform. But Romney again declined to say how he felt about the president’s latest action to help young illegal immigrants.

Romney said that he would deal with immigration reform as president and that when he makes a promise, he will keep it. The next day, Obama reminded the Hispanic audience of Romney’s vow to veto the Dream Act, which Romney didn’t mention in his address.

Romney told the NALEO audience that his priorities include tightening border controls and speeding up the visa process for highly skilled immigrants who are studying in the United States. The closest he came to alluding to his usual positions was when he told audience members that they wouldn’t always agree with him. On the question of illegal immigration, the most he would say was that he would deal with the issue in a “civil but resolute manner.”

On Monday, Romney was equally vague in his initial comments about the Supreme Court decision. On a coincidental campaign stop in Arizona, he slammed the president for what he called inaction on immigration reform. And he said that the court should recognize that each state has the right and duty to secure its borders, especially if the federal government does not do so. But he offered no hint as to whether he agrees with the court’s decision, and his spokesman declined to answer repeated questions from reporters.

Later, at a fundraiser in Scottsdale, Romney said he wished the court had given states more latitude, not less, to deal with immigration. He again accused the president of not acting on the matter when Democrats had majorities in the House and Senate. He vowed that he would take up the issue in his first year as president. He pledged that he would work across the aisle, but he did not promise specific comprehensive reform.

In all that, Romney avoided any mention of the illegal immigrants who already are in the country, an issue that has held up comprehensive reform since the George W. Bush administration. He did not talk about the opposition within his own party, which scuttled reform efforts when Bush sought a bipartisan solution. He did not allude to any of the positions he staked out during the primaries.

He promised to lead but hasn’t done so. It will be up to voters to decide in which direction they think he would go.

For previous columns by Dan Balz, go to postpolitics.com.