(CNN) - One week before a Delaware Senate debate co-moderated by CNN's Wolf Blitzer, two new polls indicate Democratic Senate nominee Chris Coons has a large lead over Republican counterpart Christine O'Donnell in the battle to win the seat held for nearly four decades by Vice President Joe Biden.
A Fairleigh Dickinson University PublicMind survey released Wednesday indicates that 53 percent of likely voters in Delaware are supporting Coons, with 36 percent backing O'Donnell.
According to a University of Delaware Center for Political Communication survey also released Wednesday, 49 percent of Delaware registered voters questioned support Coons, with three in ten backing O'Donnell and 13 percent undecided.
The survey indicates that O'Donnell leads 62 to 18 percent among Republicans, Coons leads 77 to 7 percent among Democrats and holds a 39 to 20 percent advantage among independent voters.
Last month O'Donnell upset longtime moderate Republican Rep. and former Gov. Mike Castle in the state's GOP primary. O'Donnell, a conservative commentator who launched unsuccessful Senate bids in 2006 and 2008, was supported and helped by Tea Party activists and by former Alaska Gov. Sarah Palin. Since then O'Donnell's been in the spotlight for controversial comments she made years ago when she was a spokesperson for socially conservative causes.
Coons, the executive of New Castle County, the state's most populous county, faced no serious opposition in the Democratic primary.
The Fairleigh Dickinson survey also indicates Coons' leading among Independents and O'Donnell only grabbing 68 percent support among Republican voters.
"Typically, Republicans are more loyal to their party than Democrats," says Dan Cassino, professor of political science at Fairleigh Dickinson University and survey analyst for the university's PublicMind research group. "This hesitation by Republicans is hurting O'Donnell."
According to a CNN/Time/Opinion Research Corporation poll released two weeks ago, Coons held a 55 to 39 percent lead over O'Donnell among likely voters in Delaware. Among the wider pool of registered voters, Coons' led O'Donnell by 25 points.
The CNN/Time survey indicated that if Castle had won the primary, he would be leading Coon's 55 to 37 percent in the general election match up. Last week Castle announced he would not run in the general election as a write in candidate.
Coons and O'Donnell face off October 13 in a debate at the University of Delaware that will be co-moderated by Blitzer, anchor of CNN's "The Situation Room."
The winner in November will fill out the remaining four years of Biden's final term in the Senate. Biden stepped down from his seat after his election in November 2008 as vice president. Former Biden aide Ted Kaufman was named as an interim replacement, and is not seeking a full term. After much speculation that he would run for his father's old seat, Delaware Attorney General Beau Biden announced in late January that he would instead run for re-election as Delaware attorney general. Coon's announced days later and faced no serious opposition for the Democratic party's nomination.
The University of Delaware poll also indicates that there's weaker emotional support for O'Donnell among her supporters than Coons has among his. The survey is the first released since Castle announced he would not seek a write-in candidacy.
In the battle for Castle's state wide congressional seat, which he's held for 18 years, the survey indicates that Democratic candidate John Carney holds a 48 to 31 percent advantage over Republican Glen Urquhart. According to a Fairleigh Dickinson University PublicMind poll released Tuesday, Carney leads Urquhart 51 to 36 percent among likely votes.
The Fairleigh Dickinson University poll was conducted Sept. 27-Oct. 3, with 801 likely voters in Delaware was questioned by telephone. The survey's sampling error is plus or minus 3.5 percentage points.
The University of Delaware's Center for Political Communication poll was conducted Sept. 16-30, with 901 registered voters questioned by telephone. The survey's overall sampling error is plus or minus 4.1 percentage points.