Sens. Bernie Sanders Bernie SandersJacobin editor: Primarying Schumer would force him to fight Trump's SCOTUS nominee Trump campaign plays up Biden's skills ahead of Cleveland debate: 'He's actually quite good' Young voters backing Biden by 2:1 margin: poll MORE (I-Vt.) and Elizabeth Warren Elizabeth WarrenJudd Gregg: The Kamala threat — the Californiaization of America GOP set to release controversial Biden report Biden's fiscal program: What is the likely market impact? MORE (D-Mass.) are taking their progressive star power to the campaign trail to help Democratic candidates in marquee Senate races around the country.

Democrats are hopeful the two could help energize the party's base, particularly Sanders loyalists who backed his presidential bid but may not be sold on Hillary Clinton Hillary Diane Rodham ClintonJoe Biden looks to expand election battleground into Trump country Biden leads Trump by 12 points among Catholic voters: poll The Hill's Campaign Report: Biden goes on offense MORE.

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The progressive stalwarts have already endorsed a number of candidates in races that could determine which party controls the upper chamber next year.

But having the liberal firebrands hit the trail two months before the general election is not without risks. Some worry the two could alienate centrist and independent voters.

Most political observers, though, say their involvement in down-ballot races could boost Democratic turnout and in an election where the party's nominee, Clinton, is struggling with historically low favorability ratings.

“The dilemma of course is you always run the risk, but the bigger risk right now for them is to not tap their voters’ enthusiasm, and Warren and Sanders will certainly help energize them,” said Terry Madonna, a political science professor and polling director at Franklin & Marshall College.

Sanders and Warren are launching their efforts by stumping for Democrat Katie McGinty in Pennsylvania, where she is trying to unseat Republican Pat Toomey.

On Friday, Warren campaigned with McGinty at the University of Pennsylvania in Philadelphia, a Democratic stronghold in the state. Next Friday, Sanders will visit the Keystone State to stump with McGinty, a former gubernatorial chief of staff, at Carnegie Mellon University in Pittsburgh.

McGinty is in a tight contest with Toomey. As Clinton started to rise in the polls in Pennsylvania following the Democratic National Convention in late July, McGinty ran ahead of the incumbent, though some recent surveys show him regaining the edge.

McGinty’s campaign is embracing the help, with the candidate vowing to work closely with Warren if elected to the Senate.

But Toomey's campaign quickly pounced on Warren's visit to try and paint McGinty as a candidate in lockstep with liberal policies, calling her one of the “most pro-tax increase liberal in America.”

Madonna said that with fewer Pennsylvania voters splitting their tickets, the race could come down to turnout. That could be good for McGinty if Clinton improves in the polls. Currently, the RealClearPolitics average shows Clinton with a 6 point edge over Republican Donald Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE in the state.

Both Warren and Sanders are also notably speaking at universities, making a pitch to the millennial voters who have flocked to their message.

Sanders made affordable higher education one of the top priorities in his presidential campaign. He took credit for pushing Clinton to the left on the issue when she proposed her own plan to eliminate tuition at public universities and colleges for families earning $125,000 or less.

In her pitch to Pennsylvanians on Friday, Warren touted her 2014 bill to allow students to refinance student loans and attacked Toomey for voting against it.

Political watchers think the appeal to young voters could be pivotal.

“I think that deploying politicians like Warren and Sanders particularly to college campuses might be helpful because a lot of those young voters probably supported Sanders in the primary and may not be all that excited to vote,” Kyle Kondik, managing editor of Sabato Crystal Ball.

In the final two-month stretch of the campaign, Sanders is expected to ramp up his campaigning for races up and down the ticket.

Since ending his presidential bid, the Vermont senator and his aides have vowed that he would do everything possible to support Clinton and elect Democrats. The party is hopeful of taking Senate control, with capturing the House a more difficult hurdle.

In addition to supporting McGinty, Sanders has endorsed a number of Democrats in high-profile Senate races including New Hampshire Gov. Maggie Hassan, former Ohio Gov. Ted Strickland, former Nevada Attorney General Catherine Cortez Masto and former Wisconsin Sen. Russ Feingold.

“It is very important that our movement holds public officials accountable,” he wrote in a recent fundraising email. “The Democratic Party passed an extremely progressive agenda at the convention. Our job is to make sure that platform is implemented. That will not happen without Democratic control of the Senate.”

Hassan and Cortez Masto are deadlocked in tight races with Sen. Kelly Ayotte Kelly Ann AyotteBottom line Bottom line Bottom Line MORE (R-N.H.) and Rep. Joe Heck (R-Nev.) respectively. Feingold holds a nearly double-digit lead over Sen. Ron Johnson Ronald (Ron) Harold JohnsonThis week: Supreme Court fight over Ginsburg's seat upends Congress's agenda GOP set to release controversial Biden report Democrats fear Russia interference could spoil bid to retake Senate MORE (R-Wis.). But Strickland has so far been unable to mount a tough challenge to Sen. Rob Portman Robert (Rob) Jones PortmanMcConnell locks down key GOP votes in Supreme Court fight Romney undecided on authorizing subpoenas for GOP Obama-era probes Congress needs to prioritize government digital service delivery MORE (R-Ohio) even as Clinton leads in the Buckeye State.

Sanders also recently launched a new organization, Our Revolution, to seize on the enthusiasm from his insurgent campaign and focus supporters on electing progressive candidates nationwide.

Some political observers, though, question how much of an impact Sanders and Warren will have on the cycle's top Senate races. While the two are big names for progressives, skeptics say a few visits to battleground states won't be enough to sway outcomes.

But overall, most view visits from top Democrats like Sanders and Warren as more of a plus than a negative.

“It’s hard to tell what sort of effect these surrogate visits have,” Kondik said. “My guess is it’s fairly limited, but Clinton and the Senate campaigns having some high-profile surrogates to deploy probably helps more than hurts.”

Strategists and observers believe Democrats will be careful about where the surrogates visit and send them to liberal strongholds in battleground states where they can drive up turnout.

Democratic strategist Jim Manley sees Warren being able to play in more states than Sanders and pointed to her past campaigning experience in red states like West Virginia and Kentucky when she stumped for Democratic Senate candidates during the 2014 midterm election.

“I see these as complementary,” Manley said of Sanders and Warren.

“Done right, I think together they can appeal to a wide range of the Democratic base because both bring strengths and weaknesses to some of these states.”