The last time proponents of a minimum wage hike carried the day — in 2007 — the battle took literally years to win. It took literally years to give American workers a raise from $5.15 per hour to $7.25 per hour. The battle gave rise to one of the great Senate moments — Ted Kennedy’s rousing speech, in which he unleashed a full-throated assault on Congressional Republicans, demanding: “When does the greed stop?”

Kennedy’s speech is a reminder that the battle to raise the minimum wage is an extremely difficult moral struggle, one that’s waged against very powerful opponents. I checked in with Dem Rep. George Miller of California, who was at the center of the last fight, and he admitted that the battle ahead was likely to be a very tough one.

“It’s a real slog to get it done,” he told me. “There’s an immediate negative reaction in some parts of the business community, because they don’t want to pay any more.” Miller said he expects intense opposition from the Restaurant Association and the U.S. Chamber of Commerce.

But Miller said that he and Kennedy and other Democrats were able to prevail by steadily drawing attention to the fundamental injustice that takes place as the value of the minimum wage in real dollars falls due to inflation — something which continues to happen today. (The minimum wage hike of 2007 was signed by a Republican president, George W. Bush.)

“It becomes apparent to the public that these people work very hard, in difficult and very dirty jobs, and at the end of a year of working full time, they end up in poverty,” Miller said.

In an interesting twist, Miller told me that Democrats would be reaching out to Walmart to see if it would support a minimum wage hike. The giant retailer supported one last time, arguing that it would help its struggling low income customers — who, presumably, would then have more money to spend at WalMart. The idea is that this supports the pro-minimum wage argument, which is that it leads to more spending of money by consumers.

Of course, the circumstances are very different this time. In 2007, Dems were able to get it done because they finally controlled both houses of Congress. Now the GOP controls the House.

But Miller said Dems had no moral alternative but to try anyway. He noted that various states were having success in hiking the minimum wage, suggesting the issue is good politics.

“In this current Congress, we’ll run into ideological opposition, but there’s no good time to try to pass the minimum wage,” he said. “It’s going to be tough, but it’s a battle you have to engage in. The stakes are very high for millions of workers and their families. You just have to go after it. More and more Americans will recognize that there’s an inherent unfairness here.”