Democrat Conor Lamb has pulled ahead of Republican Rick Saccone, according to an Emerson College poll conducted from March 1st through 3rd. Lamb has a slim lead, enjoying an approval rating of 48 percent to Saccone's 45 percent, in a sign that Pennsylvania's special election could see a Democrat upset.

Pennsylvania’s 18th District Special Congressional election has "garnered a lot of voting excitement," the survey notes. 56 percent of those polled say they're "very excited to vote," while only 7 percent said they're "not very excited at all." Lamb's positive image in the district appears to be helping matters:

Lamb has a positive image in the district, with 48% saying they have a favorable opinion and a 33% unfavorable rating – 15% of voters had heard of him but had no opinion. Saccone is not as popular with a 44% favorable and a 40% unfavorable rating – 15% of voters had heard of him but had no opinion.

Lamb leads 57% to 40% in Allegheny County, which is expected to account for about 42% of the vote. Saccone leads in Westmoreland County 51% to 42%, a county that comprises about 33% of the vote. Saccone leads in Washington County 46% to 41%, which make up about 22% of the vote.

The possibility that a Democrat could win a seat in a district then-candidate Donald Trump won handily in 2016 is a very real one, and more and more Congressional Republicans have shared fears that Trumpian backlash could affect their chances at maintaining their majority in this year's midterm elections.

Last month, for example, Linda Howlett Belcher, a Democrat and two-time member of the Kentucky state legislature, bested her Republican challenger 68 percent to 32 percent in a special election. That victory came on the heels of similar ones in Alabama and Virginia that appear to be harbingers of things to come as midterms draw nearer.

As the Emerson College poll notes:

Trump won the district 58% to 39% in 2016, and Mitt Romney fared equally well in 2012 with 58% of the vote to 41% for President Obama. Trump currently has a 47% job approval in the district with 43% disapproving, despite 46% of the district being registered Democrat. Similarly, House Minority Leader Nancy Pelosi only has a 20% approval rate, with 57% disapproving.

Pennsylvania's 18th district also seems hotly divided on two key issues:

• 47 percent of those surveyed said that they are "less likely to vote for someone running on an impeach Trump platform," compared to 38 percent who said they are "more likely" to vote for someone running on the same platform.
• 48 percent of those surveyed say they oppose the president's proposal to arm educators compares to 40 percent who say they support it.

Lamb has taken a considerably more moderate approach to gun control than other Democrats. He has not, for example, endorsed new gun laws. Instead, he has called for legislators to improve the existing background check system and to bar the mentally ill from purchasing assault weapons.

New district maps will be implemented in time for the 2018 primary to be held in May, per a Pennsylvania Supreme Court ruling which found that gerrymandered districts “clearly, plainly and palpably violates the Constitution of the Commonwealth of Pennsylvania.” The court noted that “if the governor accepts the General Assembly’s congressional districting plan, it shall be submitted to this court on or before February 15…If no plan is submitted, that court would adopt a plan based on the evidentiary record developed in the Commonwealth Court.”

Naturally, voters were asked about this issue as well: 37 percent of those surveyed said the recently redrawn Congressional maps favor Democrats, while 11 percent said they favor Republicans. 31 percent of those surveyed said they believe the maps are fair to both parties.

The PA USC 18th district Emerson College epoll was conducted March 1-3, 2018 under the Supervision of Professor Spencer Kimball. The sample consisted of only registered voters, n=474, with a Credibility Interval (similar to margin of error) of +/- 4.8 percentage points. The data was weighted by party affiliation, gender and county. Data was collected using both an Interactive Voice Response (IVR) system of landlines only and an online panel provided by Survey Sampling International (SSI).

Last week, election handicapper Cook Political Report changed its rating for the Pennsylvania special election to "toss-up" from "lean Republican." Cook changed its rating after Lamb announced he'd fundraised $3.2 million from January 1 to February 21. As CNBC noted at the time,

Lamb's campaign hits its final stretch without any more financial support from House Democrats' fundraising arm and facing a barrage of spending from Republican outside groups.

Such outside organizations have shelled out $4.8 million opposing Lamb and $2.2 million supporting Saccone, according to the Center for Responsive Politics. Conversely, outside groups spent only about $384,000 against Saccone and roughly $244,000 for Lamb.

Lamb's success comes despite attempts by the Republican opposition to House Democratic Leader Nancy Pelosi, who is a widely unpopular figure across the country. The pro-GOP Congressional Leadership Fund referred to Lamb and Pelosi as "too liberal" and criticized Lamb for opposing President Trump's tax plan.

Lamb responded with an ad in which he distanced himself from Pelosi: "My opponent wants you to believe that the biggest issue in this campaign is Nancy Pelosi. It's all a big lie. I've already said on the front page of the newspaper that I don't support Nancy Pelosi. The real issues are the ones that affect your lives."

Many critics have suggested that the president tied his decision on new tariffs on steel and aluminum imports to a campaign rally he's scheduled for March 10, three days before the special election.

But Pennsylvania's steel region appears divided on the president's proposal. Pennsylvania Republican Congressman Ryan Costello explained how the proposed tariffs could affect his district in an interview over the weekend with NPR:

It does remain to be seen what the actual policy is. This is - this could - may at the moment be similar to withdrawal of the Paris accord - right? - which pleased his supporters but has not yet happened. So it remains to be seen formally what steps are taken. The concern, though, is the unpredictability and the market uncertainty associated with what European Union and WTO nations will do as retaliation. They can be very, very sophisticated in terms of the types of industries, even the types of states or constituencies that they might like to send a message to with tariffs on us. The other element here that's deeply concerning is the president's very simplistic notion that trade wars are good, that we will win them, that it's easy and that if they don't come to play, then we just won't ship anything to them. Well, then that country is going to go somewhere else, and it means that our main domestic manufacturing could suffer as a result. So there's a lot more at play here, and it's not a simplistic, we're going to put tariffs down, and that's going to solve all the problems. It's likely to create some problems as well.

According to Patti Stroud, a resident of Burgettstown, Pennsylvania, and registered Democrat who voted for President Trump just weeks after the steel mill where her husband worked more than two decades shut down, the president “put his foot in his mouth one too many times."

"I thought we needed a big change, and boy, did we get it,” she said, noting that she has decided to return to the Democrats.