President Joe Biden is hitting the campaign trail for vulnerable Democrats after a string of congressional victories and with polls showing the commander-in-chief's approval rating inching upward.

Biden's foray into the midterm elections comes as the president's approval rating has increased slightly and Democrats are more optimistic about their chances of keeping the House and Senate. The morale boost is partially the result of Congress passing the White House's $739 billion climate and tax legislation as well as a key victory for Democrats in a New York special election for a prime congressional swing seat last month.

Biden, in particular, was in Wilkes-Barre, Pennsylvania, earlier this week campaigning with the Democratic nominee for governor. Also in attendance was Pennsylvania Rep. Matt Cartwright, who is one of the few Democrats to represent a district carried by former President Donald Trump in 2020.

"Your congressman, Matt Cartwright, is the real reason I’m here," Biden told the Wilkes-Barre audience. "He knows how to deliver for this district, which is so close to my heart."

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Joe Biden DNC rally

President Biden speaks during a rally hosted by the Democratic National Committee at Richard Montgomery High School in Rockville, Maryland, on Aug. 25, 2022. (Drew Angerer/Getty Images)

Cartwright is seen by both Democrats and Republicans as particularly vulnerable this cycle. Republicans have made the five-term congressman a top target in their efforts to flip the House.

Biden is similarly set to campaign with Pennsylvania Lt. Gov. John Fetterman, the Democratic nominee for U.S. Senate. The two are slated to march in a Labor Day parade together in Pittsburgh.

Later in the week, Biden will appear at an Ohio event with Rep. Tim Ryan, the Democratic nominee for U.S. Senate. The event will largely focus on the White House's recently passed legislation to boost the domestic manufacture of computer chips.

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Ryan, who is seen as an underdog in heavily Republican Ohio, has previously expressed uncertainty about the idea of Biden campaigning on his behalf.

"The White House is coming off some big wins, gasoline prices are steadily sinking, and the public seems to be approving of the job Biden's doing," said Brad Bannon, a Democratic political strategist. "Candidates recognize that, and they want to be on the side that has momentum."

Political strategists also say that the Supreme Court's overturning of Roe v. Wade, the 1973 landmark ruling that made abortion legal nationwide, has upset the status quo. Historically, a president's party loses seats in the first midterm election of a new White House.

President Biden is set to campaign with Lt. Gov. John Fetterman, the Democratic nominee for Senate, in Pittsburgh. (AP Photo/Gene J. Puskar)

President Biden is set to campaign with Lt. Gov. John Fetterman, the Democratic nominee for Senate, in Pittsburgh. (AP Photo/Gene J. Puskar)

Democrats were largely resigned to that reality until the special election for New York's 19th Congressional District occurred last month. Despite Biden having only narrowly carried the district in 2020, the Democratic nominee won the race by two percentage points.

The contest was seen by both Republicans and Democrats as a test of how the midterms would shape up. Republicans poured money behind Dutchess County Executive Marc Molinaro, who largely ran on the issues of crime, rising prices and the economy.

Ulster County Executive Pat Ryan, meanwhile, ran nearly exclusively on the issue of abortion. Ryan won the race thanks to high turnout in the district's Democratic strongholds.

Abortion protest

Political strategists say that the Supreme Court's overturning of Roe v. Wade has energized Democrats. (AP Photo/Paul Sancya)

"Republicans can say goodbye to their ‘Red Wave’ because voters are clearly coming out in force to elect a pro-choice majority to Congress this November," said Democratic Congressional Campaign Committee chairman Sean Patrick Maloney of New York.

Political experts are quick to note, however, that the New York results say more about the issue of abortion this cycle than about Biden.

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"There are a lot of reasons for why special elections pan out the way they do," said Richard Vatz, a political science professor at Towson University. "It's a bevy of local and national factors, but it's not always a direct referendum on the president. Most would caution against reading too much into them."

At least one Democratic candidate appears to be taking that advice. Ahead of his appearance with Biden next week, Fetterman released a statement showing that he was not in agreement with all the president's actions or lack thereof.

"It’s long past time that we finally decriminalize marijuana," said Fetterman. "The president needs to use his executive authority to begin de-scheduling marijuana, I would love to see him do this prior to his visit to Pittsburgh."