From Pennsylvania to Kentucky to Nevada, outsider candidates have pulled surprise victories over party favorites in this spring’s Senate primaries.

With the summer primaries approaching, The Hill is taking a look at five races in which someone other than the establishment candidate could end up on the November ballot.

North Carolina, June 22

Secretary of State Elaine Marshall was the surprise top finisher in the North Carolina Democratic Senate primary last month but didn’t garner enough votes to win the nomination outright.

But she’s kept up the momentum in the days leading up to the June 22 runoff.

Marshall has rolled out endorsements from Durham Mayor Bill Bell and Asheville Mayor Terry Bellamy. Her rival for the nomination, former state Sen. Cal Cunningham, has outraised her, but Marshall has almost twice the cash on hand, some $200,000.

Cunningham is the party favorite and has the support of the Democratic Senatorial Campaign Committee, which has contributed $79,980 to his campaign.

The Democrats are vying to take on Sen. Richard BurrRichard Mauze BurrOvernight Energy: Chemical safety regulator's nomination at risk | Watchdog scolds Zinke on travel records | Keystone pipeline spills 210,000 gallons of oil Overnight Regulation: Senators unveil bipartisan gun background check bill | FCC rolls back media regs | Family leave credit added to tax bill | Senate confirms banking watchdog Collins ‘leaning against’ Trump EPA chemical nominee MORE (R-N.C.). Strategists had expected Burr to be vulnerable this cycle — his seat is thought to be “cursed” because it changes parties so frequently — but recent polls have shown him leading whichever Democrat becomes the nominee.

The June 22 runoff, however, will come down to whichever candidate has the better field operation to get out the vote. Neither Democrat has run TV ads since the May 4 primary.

Washington state, Aug. 17

Republican Dino Rossi is off to a flying start since he entered the Senate primary three weeks ago. He announced on Tuesday that he surpassed 25,000 friends on Facebook and boasted earlier of raising $600,000 since launching his effort.

He’s running against a popular former footballer player for the right to take on Sen. Patty MurrayPatricia (Patty) Lynn MurrayGOP senator: ObamaCare fix could be in funding bill Collins: Pass bipartisan ObamaCare bills before mandate repeal Murkowski: ObamaCare fix not a precondition for tax vote MORE (D-Wash.).

Democrats are hoping that former Washington Redskins tight end Clint Didier takes down Rossi in the Aug. 17 Republican primary.

Didier, who was in Washington, D.C., on Tuesday for meetings with GOP strategists, got the support of Sarah Palin and Tea Party groups before Rossi decided to get in the race. And reports from the Washington State Republican Party’s convention last weekend indicate Didier was received warmly by delegates.

Didier is attacking Rossi — who was reportedly recruited by the National Republican Senatorial Committee — for being an establishment candidate, and has questioned his conservative credentials.

But Rossi has much higher name recognition than Didier, after having made two runs for governor.

Moreover, Republicans are sympathetic to Rossi after he lost his 2004 gubernatorial race to Gov. Christine Gregoire (D) by 129 votes. He lost to her again in 2008.

Colorado, Aug. 10

The Democratic Senate primary in Colorado was expected to be the real contest after former state House Speaker Andrew Romanoff (D) launched his challenge to appointed Sen. Michael BennetMichael Farrand Bennet15 Dems urge FEC to adopt new rules for online political ads Lawmakers put their beer brewing skills to test for charity Bipartisan lawmakers can rebuild trust by passing infusion therapy bill MORE (D-Colo.).

But the Republican primary isn’t turning out to be a coronation.

Former Lt. Gov. Jane Norton, the GOP establishment pick, has become embroiled in a tough contest against Weld County District Attorney Ken Buck.

Buck has surged since the GOP’s state convention in May, and Norton has had to reshuffle her campaign to cope with the challenge. If momentum continues with Buck, Norton may need real help to clinch her party’s nomination.

Buck is a favorite of the Tea Party movement. Norton has received praise from Palin, but the former governor of Alaska has not officially endorsed her.

Meanwhile, Romanoff has not become the left’s new Bill Halter, the Arkansas Democrat who challenged Sen. Blanche Lincoln (D-Ark.) in the primary and received millions of dollars in support from liberal groups and labor unions.

Both Colorado Democrats have some union backing, but neither was able to convince the Colorado AFL-CIO to lend its support. Bennet, meanwhile, has institutional support from the Democratic Senatorial Campaign Committee (DSCC) and the White House.

New Hampshire, Sept. 14

Republican Senate candidate Kelly AyotteKelly Ann AyotteExplaining Democratic victories: It’s gun violence, stupid Trump voter fraud panel member fights back against critics Dems plan to make gun control an issue in Nevada MORE was expected to easily win the fall primary, but a lingering issue from her time as attorney general could derail her candidacy.

Ayotte testified on Monday to the state legislature that she had no knowledge about a Ponzi scheme that was run by failed mortgage firm Financial Resources Mortgage Inc. (FRM).

“As the record makes clear, I had no personal knowledge of this matter,” she said at the hearing.

Critics have said Ayotte, national Republicans’ favored candidate, did nothing to stop the fraud that occurred during her time as New Hampshire’s top law enforcement official.

Democrats plan to hammer away on the issue.

“Kelly Ayotte was willing to take credit for creating a mortgage fraud task force, but unwilling to take responsibility for the failures of her office to prosecute FRM’s fraud,” Mark Bergman, a spokesman for Democratic Senate candidate Rep. Paul Hodes, said in a statement Tuesday.

Ayotte’s main competition comes from deep-pocketed businessman Bill Binnie, who has flooded the airwaves with TV spots. A recent poll by Colorado-based Magellan Data and Mapping Strategies showed Binnie within single digits of Ayotte.

The Magellan survey had Ayotte with 38 percent and Binnie with 29.

There are seven candidates in the GOP field, including businessman Jim Bender and conservative attorney Ovide Lamontagne.

Bender attacked Ayotte’s testimony.

“True leaders don’t let their hands get tied. They protect the people they serve, they seek truth and they push obstacles out of the way,” Bender said.

Hodes is uncontested for the Democratic Senate nomination in the Granite State.

Florida, Aug. 24

Rep. Kendrick Meek (D-Fla.) didn’t get much attention as the drama of Gov. Charlie Crist’s departure from the Republican Senate primary unfolded. But now Meek’s locked in a primary and getting more attention than he wants from his well-funded challenger.

Real estate mogul Jeff Greene has spent close to $5 million on five TV ads, a Florida-based strategist said.

He’s also sent direct mail to Democratic households, including a four-page mailer that unfolded like a poster.

Meek has stayed off the air, but he’s getting institutional support from the Florida Democratic Party and the DSCC.

“We are committed to Kendrick Meek,” DSCC Chairman Bob MenendezRobert (Bob) MenendezSenate ethics panel resumes Menendez probe after judge declares mistrial Judge declares mistrial in Menendez bribery case Menendez jury deadlocked, ordered to keep trying MORE (N.J.) told reporters last week. “I’m focused on having Democrats support Kendrick Meek.

“We believe that he can win the general election.”

Menendez said Greene reached out to the committee to inform it he was planning to run but hasn’t had any other contact.

Meek’s expected to get through the primary, but he’ll likely have to use some of the resources he would have saved for the general election, where he’ll face a tough fight with independent candidate Crist and Republican candidate Mario Rubio.