As Republican presidential candidates prepare for the debate Wednesday, several have taken on specific issues that are viewed as either important to voters or important to the candidate. To name a few, Donald Trump’s focus, as always, is immigration, while Marco Rubio tackled college reform and Mike Huckabee’s fighting against abortion and Planned Parenthood. And now, Scott Walker has made ending federal labor unions a top priority for his campaign. Considering that public employee unions are one of the things that make the federal government as inefficient as it is, Walker’s proposal is intriguing.

Walker has had enormous success as governor of Wisconsin on this issue. In fact, the battle garnered national attention and is essentially the reason he’s a presidential candidate. After being in office for only six weeks, he proposed and succeeded in ending collective bargaining for public employees in the state. Democrats in the legislature literally fled the state to avoid a losing vote. They returned when it became clear defeat was inevitable, but they also forced Walker into a recall election in 2012. Despite protests from union supporters and millions in special-interest money flooding into the state, he won — by a wider margin than his initial victory. He then won re-election in 2014. Earlier this year, he made Wisconsin a right-to-work state.

With all of the issues facing our nation, however, why is Walker choosing to focus on eliminating federal labor unions? There are a couple of factors to consider here. First, we repeat: He had great success fighting against Big Labor in the state of Wisconsin. It worked at the state level, so why not try it at the federal level?

Second, taking on Big Labor has not been talked about much amongst the GOP candidates thus far and Walker needs an issue that separates him from the pack. As The Wall Street Journal notes, “[T]he plan to severely limit labor-union rights nationwide is Mr. Walker’s attempt to force other candidates to respond to his proposals, rather than the other way around.”

The campaign spotlight is no longer on Walker like it is on Trump, Carly Fiorina or Ben Carson. In fact, Walker has plummeted in the polls. Early in the race, he was the frontrunner in Iowa. Now he has fallen to 10th place with just 3% support in a recent poll. He is no doubt hoping that taking on federal labor unions as a big part of his campaign platform — returning to his roots, as it were — will boost his numbers.

Walker highlighted several reasons that labor unions are detrimental to the federal government — and America.

“In 2012, American taxpayers shelled out some $156 million to do the bidding of big-government union bosses. Federal workers spent more than 3.3 million hours that year doing union work, instead of serving the government.”

Further, he explains that political donations from federal unions overwhelmingly go to leftist candidates and causes, and that’s been true “for decades.” The reason is simple: Unions have a self-interest in growing government, and Democrats promise to deliver.

Federal unions are also a “force for making our government less efficient and accountable,” Walker said, as evidenced by union bosses who have a grip on the Department of Veterans Affairs. Several employees at the VA should have been demoted or fired for poor performance or misconduct in the wait-time scandal, but because of labor unions they were allowed to stay — and even received back pay.

Walker contends that federal unions “interfere with the ability of government to serve people.” He specifically points to the IRS, which has “more than 200 employees work[ing] full-time for big-government union bosses at taxpayer expense” — all while the agency is targeting conservative political groups.

So what exactly does Walker intend to do to fight against federal labor unions if he is elected president? Reason’s Scott Shackford points out five key areas:

• Eliminate the National Labor Relations Board — He will transfer power to the National Mediation Board and the courts, but he will need cooperation from Congress to change existing federal law.
• Eliminate federal unions — He promises to end taxpayers subsidizing millions of hours of union lobbying.
• Establish nationwide right-to-work — He proposes that all states be made right-to-work unless a state enacts a law saying it is not a right-to-work state.
• Prohibit forced dues from government workers for political purposes — He’ll end forced dues from those who don’t want to pay, and would protect employees from harassment and threats from union organizers. He would also protect whistleblowers who report union wrongdoing.
• Dump regulations that drive up federal construction costs — He proposes a repeal of the Depression-era Davis-Bacon Act, which forces the federal government to pay artificially inflated “prevailing wages” for construction projects, as well as ending labor agreements that guarantee highway construction projects to union-only labor.

Walker has gone from frontrunner to long shot, and while the issue may not hit home with all voters, it will resonate well with those who despise the corrupting power of labor unions. We will see on Wednesday how much attention Walker devotes to the issue during the debate. And we will know soon whether focusing on this issue makes or breaks his campaign.