NASHVILLE, Ind. - Political analysts across the nation have their eyes peeled on Indiana - the center of the political universe this weekend - to see if momentum shifts away from Hillary Clinton and back to Barack Obama in the final hours before the crucial May 6 primary. The activities of the campaign lend credence to analysis at Tuesday's Howey-Gauge Poll Briefing: that Hoosier Republicans and independents may hold the key to victory. Howey-Gauge Poll estimates that up to 20 percent of voters in the Democratic primary will be Republicans and independents.

With the Real Clear Politics poll composite showing a 6 percent Clinton lead, former President Bill Clinton was pounding normally Republicans areas such as Warsaw, Plymouth, Angola and Kendallville while Sen. Clinton was planning events in Fort Wayne, South Bend and Indianapolis. Barack Obama was planning a mid-Saturday afternoon event in Noblesville, one of the most Republican cities in one of the most Republican counties in the nation. Obama was also meeting with a family in tiny Kempton, Indiana. He winds up his campaign with a Monday evening rally at the American Legion Mall in Indianapolis.

The latest Zogby Poll - the last poll released at this writing - had Obama leading Clinton 43-42 percent, suggesting that the momentum that appeared to be benefitting Clinton was beginning to wane. The two Democrats sparred fiercely on Clinton's proposal for a federal gasoline tax holiday this summer. Hillary Clinton signs autographs in Kokomo Wednesday night. The 2nd CD is one of the districts up for grabs. (HPI Photo by Ryan Nees)Clinton said that families needed the relief so they could take "family vacations" this summer. But Obama and virtually every economist and even her political allies such as New York Gov. David Patterson said such a move would not be wise. There is little hope that Clinton could muster the Congressional support to impose the windfall tax on oil companies as she has talked about on the campaign trail. Obama said in Munster that the plan would save the average drive about 30 cents a day, "not enough to buy a cup of coffee at 7/11."

There was also late developments in the Magnequench story, when ABC News reported that Sen. Evan Bayh had complained to the Clinton administration about the plant's sale to a Chinese company. It later moved its operations to China. Clinton campaigned on the issue in mid-April and had based a campaign TV ad on the issue. Whether Obama can score points and support off the gas tax and Magnequench issue remains to be seen.

Perhaps the most critical development for Obama came on Wednesday and Thursday, when U.S. Rep. Baron Hill and super delegate Joe Andrew, the former Indiana and DNC chairman, endorsed Obama. Andrew shifted his support from Clinton. While the endorsements might have only headline value (Andrew was described as a "weasel" by Ann DeLaney on Indiana Week in Review Friday evening), what they did was shift the national news media away from the Rev. Jeremiah Wright story to another topic. Many believe Obama's poll dive corresponded with the Rev. Wright story. Since the Andrew and Hill endorsements, the campaign settled on the gas tax issues, also good news for Obama.

Barack Obama talks at a more intimate setting at Garfield Park in Indianapolis. His final weekend in Indiana will be centered on smaller, family oriented events. (HPI Photo by A. Walker Shaw)Obama is expected to get a lift in Southern Indiana where the most influential political figure there - former congressman and 9/11 Commissioner Lee Hamilton - was planning to barnstorm Saturday and Sunday to cities such as Evansville, Corydon, Madison, Columbus, Seymour and Bloomington. The Hamilton tour has the potential to shift momentum away from Clinton, who has been widely favored in the 8th and 9th CDs.

HPI analysis believes that Obama will do well in Lake and Marion counties - the 1st and 7th CDs, and possibly the 3rd CD. Clinton appeared to have advantages in the 5th (the irony of Bill Clinton campaigning deep in U.S. Rep. Dan Burton's district was delicious), 8th and 9th CDs. The battleground districts appear to be the 2nd, 4th and 6th CDs.

Here are some telltales HPI is looking for in the final 72 hours:

GAS TAX DEBATE: Will Hoosiers understand the nuanced argument that Obama is making against the gas tax suspension? It worked for Gov. Frank O'Bannon during his 2000 re-election bid. Will Hoosiers see history repeating itself eight years later and make the connection that the status quo is responsible for the soaring gas prices and into Obama's wheelhouse of change? Or will Clinton win on what could be perceived as a populist message?

ORGANIZATIONAL TURNOUT: Obama began the Indiana primary sequence with an organizational advantage, one he still may possess. Democratic observers tell HPI that his campaign has been far more active on the VAN - the statewide voter list - than Clinton. Of the 127,000 people who have already voted, 20 percent of those came from Obama strongholds of Lake, Marion and Monroe counties, an indicator that the Obama campaign is pinpoint targeting its GOTV. The Obama campaign has long promoted early voting. In addition, the Obama campaign signed up 90,000 of the 200,000 newly registered voters. A key question is, how many of those people showed up in polling of "likely registered voters"? A number of observers we talked to said the wildcard is how the 200,000 new voters will behave.

AFRICAN-AMERICAN SUPPORT: HPI has heard anectdotally that some African-American precincts could vote in the 80th or 90th percentile, when typically they vote their primary participation would be in the 20th percentile, depending on local races.

RACISM: Are the polls accurately reflecting any racial bias? This element would favor Clinton, who is expected to do well with white blue collar voters.

FEMALES: HPI has heard estimates that between 58 and 60 percent turnout could be female. If that holds, Clinton would benefit.

JEFFERSON-JACKSON DAY DINNER: The capstone of this historic Indiana primary will be Sunday evening's Jefferson-Jackson Day Dinner. It will draw a national audience, and certainly media coverage will also be intense throughout Indiana. Can Obama temper his "soaring rhetoric" and deliver a message that will appeal to the blue collar voter who may see him as too intellectual? The challenge for Clinton, who is at a severe disadvantage in the delegate count, is to make a case that by continuing her uphill battle, she won't be destroying the Democratic Party's prospects in November. Sen. Bayh is expected to introduce Clinton while Hamilton will introduce Obama. They are the two most influential Democrats in Indiana.

HPI ANALYSIS: We saw the momentum swing to Clinton after the Pennsylvania primary through mid-week. We believe that hits its apex and may be shifting into the weekend. We believe this race is too close to call.