With 19 days left until Election Day, Sen. Robert Casey (D-Pa.) has a real race on his hands against a well-funded Republican opponent who has blanketed the airwaves with ads propelling himself into competition. Democrats are not panicking, but for the senator with the well-known last name, it's going to take more than family ties to pull out a win.

(Leigh Vogel -- Getty Images)

A Quinnipiac University poll released Tuesday showed Casey with a slight, 48 percent to 45 percent lead over self-funding Republican Tom Smith. Other surveys have showed Casey with a more comfortable advantage, but it’s clear the race is competitive.

The main reason Casey has had to sweat is Smith’s money. The Republican loaned his campaign a whopping $10 million during the third quarter, suggesting he thinks he has a serious shot at victory. All told, he’s poured in about $17 million, much of which has gone toward TV ads, which have splashed all over the airwaves in recent months.

"Tom Smith's relentless TV ad barrage has lifted him out of the coal mine to give Sen. Robert Casey a run for his money," said Tim Malloy, assistant director of polling at Quinnipiac. "Casey had a 55 - 37 percent lead in Quinnipiac University's August 1 survey. Now this race is too close to call."

Casey’s campaign insists it hasn’t been taking Smith lightly, and says the media is just now taking a closer look at the contest. 

“We have been trying to raise alarm bells for a while now,” said Casey campaign manager Larry Smar. “Until the last poll came out in September, no one was paying attention to the race.”

Casey’s third quarter fundraising haul didn’t send the signal that he is ready to throw a knockout punch. He brought in about $1.5 million – a tick less than Smith raised. It’s notable enough that a Republican challenger outraised a well-known Democratic incumbent. It’s more remarkable that it was Smith, who doesn’t really even need to raise cash to compete. 

Smith campaign manager Jim Conroy said the third quarter tally "is even further evidence that Casey's message is falling on deaf ears."

The money race is a long one, and Casey has steadily built his campaign account quarter after quarter. He ended September with over $5 million in the bank, meaning he had enough cash for significant TV ad buys. The battle over the airwaves has become much more even during the past couple of weeks. Smith no longer has the airspace to himself. 

That's one reason Democrats aren't panicking. Another is the realistic expectations many held. Several strategists say they never expected the race to be as one-sided as it was earlier this year, before Smith began has major air campaign. 

“I think the mistake people are making right now is looking the Senate race in the context of where it was and not where it should be,” said one Pennsylvania Democratic strategist unaffiliated with Casey’s campaign who was granted anonymity to speak candidly. 

Another Pennsylvania Democratic strategist not working for Casey said the way Smith's messaging has resonated may have caught Casey's team "a little bit off guard," but still sounded very confident the incumbent would win. 

Ed Rendell, the former Democratic governor of Pennsylvania, said he expects Casey to win by a margin between "four and seven points."

So far, neither the National Republican Senatorial Committee nor the Democratic Senatorial Campaign committee has entered the air war. If national Democrats enter the fray, it would be the surest sign yet that Casey is in some real trouble. 

Smith has put himself in a solid position, but he’ll likely have to outrun the top of the GOP ticket to win in November. While recent polling shows Mitt Romney is within striking distance of President Obama in the Keystone State, the GOP presidential candidate hasn’t won there since 1988. Meanwhile, Romney’s campaign hasn’t spent any money on TV there, suggesting it isn’t too optimistic about its odds in the state. 

Looking ahead, Smith and Casey will debate on Oct. 28, giving voters a chance to compare the two candidates side by side.

What's clear in this race is that Casey will have to really earn a reelection win, as Smith has done a good job keeping himself in the conversation. A competitive Senate race in Pennsylvania may have seemed to some observers like a stretch a few months ago. But that's what this contest looks like right now.