Washington, Nov.4 : Absentee and early voting could make it difficult to forecast preliminary results in the presidential polls on Tuesday evening.
Some political observers predict early and absentee voters will make up about 30 percent of the total votes on Election Day -- which could approach a record 130 million to 140 million.
And state-by-state statistics consistently show Democrats dominating Republicans in early turnout. That means exit polls based on Tuesday-only voting could trend more toward John McCain over Barack Obama.
"The Election Day vote tends to be more Democratic in the past. This election looks like we're going to flip that around, and I think we have to really be careful in how we interpret those numbers," Fox News quoted Michael McDonald of George Mason University, as saying. "I just hate the exit polls being used to declare winners," said Curtis Gans, director of the Center for the Study of the American Electorate at American University. And this year is no different, he added.
"In this particular case, we may have some inaccuracies," Gans said.
The McCain campaign concurred that exit polling could be inaccurate -- but warned that it historically trends Democratic and issued a call to "discourage a rush to judgment based on the exit polls."
While exit polls could skew the story one way, early tabulations released by states that allowed early voting could trend the other.
This might not matter in tiny, predictable states like Arkansas or Vermont. But critical battlegrounds like Florida, Ohio and North Carolina have seen hundreds of thousands of residents come out for early voting.
In North Carolina, more than 2.5 million people participated in early and absentee voting -- and Democrats outnumbered Republicans by nearly 2-to-1.
In Florida, over four million voters used those forms of voting -- 2.6 million people participated in early voting alone. Registered Democrats held about an 8-point advantage over registered Republicans in that turnout.
However, polls from those states don't show Obama running away with the election. Rather, early voting figures suggest McCain's prediction that voters are in for a late night may come true.
Election experts have a hard time gauging whether early voting programs, which are used in more than 30 states, are responsible for high turnout this year.
Either way, turnout on Tuesday could be historic, once all the figures are tallied. n terms of the sheer number of votes, the record was set in 2004 when 122 million people voted. The highest turnout percentage of the past two centuries was set in 1908, when 66 percent turned out for the general election. The next highest was set in 1960, when 64 percent turned out.
Experts predict Tuesday's numbers could at least represent the highest turnout percentage since 1960.