Updated

To read reports back in February when New Castle County Executive Chris Coons dared to jump into the Senate race to challenge one of Delaware's most popular politicians, Republican Rep. Mike Castle, the young Democrat might as well have been committing political suicide.

Vaunted campaign prognosticators rated the race back then "Solid Republican, " but Vice President Joe Biden, who's former Senate seat (for 36 years) the two men are vying to take, said at the time, "I predict to you that Chris Coons is going to surprise the devil out of them."

And he appears to be doing just that. His slow but steady rise in the polls, coupled with a first for Castle as he dipped below the 50 percent mark in a mid-July Rasmussen poll, has some Republicans scratching their heads in wonder. Could this be a sleeper race?

By all accounts, Castle is the odds-on favorite. Cook Political Report senior editor Jennifer Duffy says the Republican still has a comfortable lead with plenty of money in the bank, there has been no "forcing event" - that is, an unpredictable game-changer, so the respected publication sees no reason, as yet, to change its rating for the race from "Leans Republican."

"Part of it is Castle. He was the candidate Republicans needed to run," Duffy said, though noting, "No doubt, Castle does have a race."

Democrats did not get their first choice in Chris Coons, though. Vice President Biden's own son, Beau, was expected to run when President Obama tapped his father for the White House job, but the state attorney general shocked the political masses and chose, for a variety of reasons, to remain in his current position.

Democrats then quickly embraced the young, energetic county executive, trying to hold onto the seat that would have comfortably stayed in Democratic hands under Sen. Biden, while Republicans relished a potentially embarrassing pick-up that could also include the Illinois seat Obama once held, as well.

But recent polling has given Democrats some reason to hope. While an earlier Rasmussen poll in April had Castle at 55 percent to Coons' 32 percent, Coons has closed the gap significantly. Rasmussen now puts Castle at 47 percent with Coons rising to 36.

And that has national Democrats smiling. "I think it is a race that people aren't paying attention to and that we have a tremendous opportunity to win for a variety of reasons. Coons has cut the lead in half based on pure shoe leather...He is a dynamic candidate, a bundle of energy," Democratic Senatorial Campaign Committee Chairman Robert Menendez, D-N.J., said, embracing a poll Democrats often deride as being too weighted to Republicans.

The 46-year old county executive clearly has an uphill climb, but a number of factors are tilting in his favor, factors that make this a race to watch. Coons is from Delaware's most populous of its three counties in a blue state that voted for Obama in 2008 by 67 percent, and Coons is a strong orator with a dynamic family picture and an exuberant energy that will make it possible for him to get around this small state and without spending a lot of cash in doing so.

Political experts say that a shortage of cash is, for now, Coons' biggest problem. Indeed, Castle's war chest is more than two and a half times his opponent's. But, while Menendez conceded the cash deficit, he also made it clear that Democrats will be there to help, although the chairman would not say exactly what the DSCC will do.

Senate Whip Dick Durbin, D-Ill., recently held a fundraiser for Coons in his home state. "He turned out a heck of a crowd, and here's a guy with no base in Chicago and really made a great presentation," Durbin gushed, adding, "As senators say from smaller states, he's a cheap date. It doesn't take much to give him a viable campaign, we're not talking millions for him to be viable. And he has closed the lead."

But television advertising can be pricey in Delaware, which shares an ad market with Philadelphia, and advertising is critical to hammering home a message should the race tighten further as some predict. Sophisticated voter turnout operations can also be dependent on a cash-flush candidate, though Delaware is small enough to minimize, to some extent, a financial disadvantage, particularly if there is outside assistance.

Still, one GOP strategist dismissed Coons' chances in the money game, "His campaign is having trouble getting off the ground. It just came out that he had to give himself a $250,000 loan last quarter, and Castle has vastly outraised him."

At 71 years old, Castle chose to leave his comfortable at-large House seat he has held for nine terms, and Democrats are clearly ready to make his age an issue, as well as his voting record.

"Castle seems to be tired, and most importantly, he moved in a direction totally opposite of where he has been in the past, more extreme," Menendez accused, referencing the congressman's vote against the $862 billion stimulus legislation, as well as health care reform.

"It's a fairly pathetic cheap shot to invoke the age card, but particularly ironic coming right after the DSCC just spent over a million dollars trying to re-elect Arlen Specter who is 10 years older than Mike Castle," blasted the GOP strategist, who also noted that Castle recently co-sponsored the Democrats' signature campaign finance legislation to curb political spending by corporations and unions.

Democrats are also hoping history provides a roadmap to victory. In 1972, a young, 29-year old named Joe Biden toppled popular two-term incumbent Sen. Caleb Boggs, recounted Sen. Tom Carper, D-DE. "Boggs had been our governor, our congressman, our senator. He was chairman of the National Governor's Association...He was beloved. People loved him, but he was older, in his 60's, and he was tired," Carper said, echoing Menendez's line of attack, noting also that he, himself, successfully toppled an entrenched GOP incumbent in 2000 when he defeated Sen. Bill Roth with a message: "A Senator for Our Future."

Duffy took issue with the Democrats' attempted analogy, however, saying Bill Roth, unlike Castle, was "in particularly bad health. He passed out twice on the campaign trail." And, Duffy noted, both Biden and Carper "got to govern in better times."

While Democrats intend to focus on Castle's age and voting record, Castle appears to be adopting the broader GOP fiscal responsibility message this fall, as well as pointing out the perils of one-party rule.

"Delaware is a small enough state to travel in a few hours and the Congressman is up and down the state more than any candidate here. Delawareans trust Mike Castle and value his independence. This race is about reflecting the needs of the voters and they don't want a rubber stamp in the Senate for the Administration's spending tends," said Castle campaign aides in an e-mailed statement to Fox.

Though Castle does have to divert some time and energy at defeating Tea Party challenger Christine O'Donnell, who recently polled well against the incumbent, political experts predict the perennial conservative challenger does not, at least for now, pose a danger.

One notable factor in this race is its remarkable civility, though the age issue appears to run the risk of changing the tone. Still, for now, the lack of acrimony is notable, not the least of which because it keeps the national spotlight off the race. One senior Democratic aide with decades of experience in campaigns, told Fox, "If you had to pick a model of how a race should be run, I don't think you could even create a race as calm and civilized as this one. It's down right boring. It's the endangered species of midterm elections, and we haven't quite figured out if that's a plus or a minus for our guy."