Wisconsin Gov. Scott Walker (R) officially has an opponent. And she will have a tough time unseating the incumbent.

(Andy Manis/Associated Press)

Mary Burke, the former bicycle company executive and state commerce secretary announced her campaign on Monday with a simple message: jobs, jobs, jobs.

Democrats are bullish on Burke, and there are justifiable reasons for them to be. But the reality is that running against Walker will be no small task, for several reasons.

For starters, he's already survived what looks to be the worst of the backlash against him. His law curbing collective bargaining for public employees triggered widespread anger among organized labor and was responsible for a slate of state Senate recall elections in 2011 and an effort to expel Walker from office in 2012. But he survived, winning by a greater margin than when he was first elected in 2010.

Secondly, it's historically been pretty difficult to unseat incumbent governors in Wisconsin. They have won more than 70 percent of the time.

Wisconsin voters were split over Walker in the most recent Marquette Law School poll with 48 percent approving of the job he's doing and 46 percent disapproving. That's hardly safe territory, but it's not territory that suggests Walker is among the most vulnerable governors in the nation.

Most voters in the survey said the economy will either get better or stay about the same, looking ahead. Voters need an overwhelming reason to replace incumbents on certain issues. And given the lack of overwhelming pessimism about the economy (which tends to be the focal point in most campaigns) it will be tough for Democrats to win on that issue alone.

The encouraging data point in the poll for Burke is that a plurality (48 percent) said Wisconsin is lagging behind other states when it comes to job creation. Job creation is going to be the centerpiece of Burke's campaign. The announcement video she released Monday made that clear.

Money will also be a big factor in this race, and Walker will have lots of it. His push to curb collective bargaining and budget cuts have won him deep loyalty from well-heeled conservative groups. And his position as vice chairman of the Republican Governors Association has opened doors to more money.

Burke, it's worth noting, is independently wealthy and is capable of self-funding a campaign. But it remains to be seen just how much money she will pour into her bid.

Finally, the fact that the election takes place in a non-presidential year is good for Walker. President Obama carried the state twice, but Democratic turnout isn't expected to be as robust as it was in 2012 and 2008.

The bottom line is this: Burke is a pretty solid recruit for Democrats with lots to prove. Walker has already proven that he's a survivor and the fundamentals favor him.

This is definitely a race worth watching -- just don't count on a Walker defeat.