Pennsylvania Republican Rep. Keith Rothfus isn’t particularly worried about a new poll that showed his fall opponent, Democratic Rep. Conor Lamb, in a strong position in the 17th District race. 

The Monmouth University poll released Tuesday showed Lamb with at least a 10 point lead under three different turnout models in the western Pennsylvania district.

Rothfus pointed out that a sizable number of voters in the newly drawn district aren’t familiar with him yet, thanks to Pennsylvania implementing new congressional lines earlier this year.

“I think you take a look at the new district, half the district, people don’t know me,” the three-term congressman told Roll Call as he walked to the House floor Tuesday afternoon. “So I’m out there and I think you’ll have a much different result on election night.”

Fifty-one percent of respondents to the Monmouth poll backed Lamb compared to 39 percent for Rothfus in the full voter sample, which had a 4.9 point margin of error. Nine percent were undecided.

Adjusting for a historical midterm turnout, the poll found Lamb ahead, 53 percent to 40 percent, with a 5.2 point margin of error. The Monmouth University Polling Institute surveyed 401 voters via telephone from July 19-22. 

Watch: Iowa’s Blum Now Most Vulnerable House Member, Nelson Moves Up List for Senate

Redistricting in Pennsylvania shook up the general election contests and made Rothfus’ re-election much more competitive. The 12th District seat he holds shifted from one that President Donald Trump carried with 59 percent of the vote in 2016 to one that would have backed him with 49 percent of the vote — or by 2 points — under the new lines.

Asked if he was approaching this race differently than past elections, Rothfus said, “We have a good record — a good record on Medicare issues, a good record on helping the district and getting the economy rolling again. So, no, we’re really confident.”

Lamb’s current 18th District, which he won in a special election in March, became much more Republican when it was redrawn as the new 14th. So he decided to challenge Rothfus in the new 17th, where he also lives.

According to an analysis by Daily Kos Elections, more than half the voters who Rothfus currently represents are now in the new 17th District. Conversely, just 20 percent of Lamb’s voters are in the new 17th.

But Lamb enters the race with high name recognition thanks to immense media attention from his surprise special election victory in a district that Trump had carried by 20 points. The win also boosted Lamb’s fundraising. Both he and Rothfus ended the second fundraising quarter on June 30 with nearly $2.1 million in the bank.

The newly competitive race and Lamb’s strength as a candidate make Rothfus one of the most vulnerable House incumbents.

Inside Elections with Nathan L. Gonzales rates the 17th District general election a Toss-up.