Control of the Senate has long seemed destined to return to Republicans in November 2022. Political strategists have cited past elections that resulted in the party that controls the White House losing in midterm elections.

With President Joe Biden suffering from low approval ratings and growing uncertainty surrounding inflation and rising prices, the Democrats' chances of retaining legislative power were growing slim.

However, a lot has changed since the beginning of the summer.

The Supreme Court's overturning of Roe v. Wade has boosted both Democratic engagement and fundraising. The Jan. 6 Committee has once again placed former President Donald Trump in the spotlight and Trump has faced additional scrutiny with the FBI search of his Mar-A-Lago residence.

These events have shifted the focus of the midterm elections from a referendum on Democratic governance to a choice between the two major parties.

Throw in the slate of legislative successes Biden accomplished over the summer, including the signing of the Inflation Reduction Act, and Democrats once again have hope of retaining the 50-50 split they currently hold.

The actions of Trump and Biden are not the only factors that will come into play during these midterms. Candidate quality has been a point of emphasis for Republicans, as many candidates faced grueling primaries only to find themselves in surprisingly close general elections.

Senate Minority Leader Mitch McConnell expressed his concerns over the quality of certain Senate candidates, noting that this factor could hamper Republicans' chances of flipping the chamber.

"I think there's probably a greater likelihood the House flips than the Senate," the longtime Kentucky senator said in his home state. "Senate races are just different, they're statewide. Candidate quality has a lot to do with the outcome."

Here are the most intriguing Senate races, in order of most likely to flip:

Pennsylvania

Progressive Democrat John Fetterman, who won his primary just days after suffering a stroke, is thus far outperforming his Republican opponent, Dr. Mehmet Oz. While the stroke kept Pennsylvania's lieutenant governor off the campaign trail for several months, he has continued to hold his ground against the ex-television star. Fetterman has gone after Oz for his wealth and residency status, using social media to boost his message.

However, this race is far from over as Oz is still within striking distance. The Republican attacks on Fetterman's health aren't sticking, but Oz has found success attaching Fetterman to rising crime and an anti-fracking position. Oz won his way through a hotly contested primary, using a Trump endorsement to elevate him past ex-hedge fund CEO David McCormick.

FiveThirtyEight currently has this race as leaning Democrat, with Fetterman winning 72 out of a simulated 100 outcomes.

Georgia

Georgia has remained close since the outset. Incumbent Democratic Sen. Raphael Warnock, the pastor at the same church Martin Luther King Jr. once frequented, has done well so far. Republicans have had trouble painting the moderate as "radical," changing their strategy to portray Warnock as out of step with Georgian values.

Warnock's opponent, former NFL running back and Trump-endorsed candidate, Herschel Walker, has recently been mired in controversy. Still, the former University of Georgia running back has incredibly high name recognition and appeal amongst Republicans. Walker has been able to juke his way past numerous gaffes and accusations to make the race close.

FiveThirtyEight currently has Raphael Warnock as slightly favored to hold onto the seat, with the Democrat winning 59 out of a simulated 100 outcomes.

Arizona

Incumbent Democrat Mark Kelly has a growing lead in the polls and has been able to carry his moderate profile to success in a state that Biden narrowly won. Trump-endorsed Republican Blake Masters won his primary on the margins and has continued backing the former president's false stolen election claims. However, as election day nears, experts on both sides believe this race will tighten.

Masters has generated controversy on his own, but Democrats have chosen to focus on his hardline-abortion stance. In one of the first post-primary ads run by Democrats, they highlighted a perceived disconnect between Masters and Arizonans.

Republicans have attacked Kelly on topical issues such as inflation and crime, and local issues such as immigration. In a state where Republicans outnumber Democrats by about 147,000, independents are key for a Kelly victory. Democrats have been able to win over independents in recent Senate elections in the state, but it's a tougher task in the first midterm of an unpopular Democratic president.

FiveThirtyEight currently has Kelly as favored to retain his seat, coming out on top in 81 of a simulated 100 possible outcomes.

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