* I don’t know why anybody would publish poll results that include data as old as 25 days, but whatever, here are the numbers…

Democratic Illinois Governor Pat Quinn enjoys a two and one-half point lead among registered voters over Republican challenger Bruce Rauner, according to the latest statewide poll from the Paul Simon Public Policy Institute at Southern Illinois University Carbondale.

But when likely voters are asked for their preference, Rauner holds the two point lead.

“It’s a tied race,” said David Yepsen, director of the Institute. “No one can predict from these numbers who will win. It’s likely to be close on election night and every vote will be important.”

• Among registered voters, the survey shows 41.2 percent favoring or leading toward Quinn and 38.6 percent favoring or leaning toward Rauner. Libertarian Chad Grimm had 4.5 percent supporting or leaning toward his candidacy.

• But among the 691 respondents considered to be likely voters, it’s Rauner who holds a slim lead: He gets 42.4 percent, Quinn has 40.7 percent and 3.0 percent are for Grimm.

The full sample of registered voters has a margin of error of plus-or-minus 3 percentage points. The smaller likely voter sample has a margin of error of 3.7 percentage points. That means both leads are within margins for error, hence a statistical tie.

Among the 1,006 registered voters surveyed, Republicans held the edge in voter enthusiasm, with half (49.8 percent) saying they were more enthusiastic to vote than usual, compared with barely a third (31.4 percent) of Democrats and Independents (29.5 percent).

On the other hand, Democrats held the edge in the generic vote for US House of Representatives, with 46.6% favoring or leaning toward the Democratic House candidate and just 33.1% leaning toward the Republican candidate. Among likely voters, the margin shrank to 43.3 percent for the generic Democrat and 37.6 percent for the Republican.

“If every vote is important, then Republicans have the easier turnout task, since their folks are clearly more excited about the election,” Yepsen said.

Discuss.