A new poll in the Illinois gubernatorial race has some good news for both major party candidates, but shows the race is in flux and is likely to be decided by independents.

Commissioned by the Paul Simon Public Policy Institute at Southern Illinois University, incumbent Governor Pat Quinn holds a slim lead over Republican challenger Bruce Rauner, 41 percent to 39 percent among registered voters. However, likely voters favor Rauner 42.4 percent to 40.7 percent.

Both results are within the poll's margin or error. The poll also shows Libertarian Chad Grimm receiving at least three percent in each scenario.

Grimm may end up playing a visible role in the race as a candidate who has the ability to receive votes that might otherwise go to one of the major candidates. GOP supporters have sensed this and begun spreading a message, partly aimed at Republican and Republican-leaning independents, that a vote for Grimm is really a vote for Quinn.

Adding to this consternation was the revelation that Grimm received a donation of $30,000 from the International Union of Operating Engineers. As the only other option on the ballot, Republicans have seen this as the propping up of a candidate who could attract votes from Rauner.According to the

poll, Republicans have higher voter enthusiasm than Democrats, with 50 percent saying they are more enthusiastic than usual compared to the Democrats' 31 percent. However, voter enthusiasm is difficult to measure or determine if it will actually benefit Rauner.

Nearly all early polls showed Rauner with modest, but steady leads over Quinn, but his leads have all disappeared. One poll showed Rauner with a high of 51% in August and the 42% he received in the Simon Center poll is the same as the Real Clear Politics average of all polls, casting questions on the levels of GOP enthusiasm.

Rauner has attempted to differentiate himself from Quinn in an attempt to gain crossover voters and independents. He has done this largely by saying he will roll back the state's temporary income tax increase, which Quinn is seeking to extend.

However, Rauner has announced plans to increase state revenue through increasing the state sales tax and adding fees to certain services. He has also offered qualified support for a statewide $10-per-hour minimum wage. In contrast, in a survey for the Campaign for Liberty, Grimm took a stance against all tax and fee increases.

But polls in past years have shown Illinois politics can be highly fluid and unpredictable.

In 2010, nearly all polls showed Quinn losing by an average of five points, but he narrowly prevailed by about half a percentage point. A constant concern among Democrats in this year's election has been whether the unpopular Quinn might be a drag on other candidates.

Races are closely contested in the 11th, 12th, 13th, and 17th congressional districts, where Democrats won in 2012, but the GOP might claim this year. Yet, Democrats lead in the generic ballot.

With Illinois roughly split between the Republican south and Democratic north, the gubernatorial race is closely divided along those lines. With neither major-party candidate truly capturing enthusiasm, the Illinois gubernatorial race has provided an opening for outsider candidates and independent voters to make the difference.

Image: Republican Bruce Rauner (left) and Illinois Governor Pat Quinn (right)