Democratic leaders have taken an unusually aggressive approach to the party’s Senate primaries this year, offering key endorsements in competitive races where, in some cases, voters are split. Amid an anti-establishment mood, their overt involvement carries risk — though the tactic has seemed effective, so far.  

The latest example came Wednesday in Pennsylvania, where President Barack Obama and Vice President Joseph R. Biden Jr. endorsed Katie McGinty in her bid for Senate, passing over her opponent, former Rep. Joe Sestak. Last week, the Democratic Senatorial Campaign Committee announced its formal support of McGinty, a former Al Gore adviser, who polls show trails Sestak but has earned the support of many Pennsylvania Democratic leaders, including Gov. Tom Wolf and Sen. Bob Casey.  

“Katie is a true champion for working families, with a proven record of taking on big challenges and delivering for people,” Obama said in a statement. “She spent her entire career working to promote clean energy and combat climate change, and worked closely with my administration to implement the Affordable Care Act and expand Medicaid coverage to more than 500,000 Pennsylvanians.”  

The endorsements from Obama and Biden are a mild surprise given their timing less than two months before the state’s April 26 primary. Also, many Washington Democrats maintain their belief that Sestak, who was the party’s 2010 nominee for Senate, can also defeat vulnerable Republican incumbent Sen. Pat Toomey in the fall.  

But heavyweight endorsements are hardly unusual this election cycle, even in competitive primaries. In Ohio, North Carolina, and Illinois, the DSCC backed former Gov. Ted Strickland, onetime state Rep. Deborah Ross, and Rep. Tammy Duckworth, respectively, despite opposition from spirited if underfunded challengers. Obama and Biden have also thrown their names behind Strickland, who would challenge vulnerable Sen. Rob Portman of Ohio come November.  

In Florida, the party has been even more aggressive in picking favorites between Reps. Patrick Murphy and Alan Grayson in the race to fill GOP Sen. Marco Rubio’s open seat. Obama, Biden, and the DSCC have all endorsed Murphy over the combative Grayson ahead of the state’s late Aug. 30 primary. Senate Minority Leader Harry Reid, meanwhile, has called on Grayson to drop out of the race.  

On Monday, Biden attended a fundraiser for Murphy in south Florida, a sign that the executive branch leaders plan to do more to help than an endorsement in name only.  

Democratic leaders say they have endorsed candidates — in each case, in a state whose Senate seat is held by a Republican — with the best chance to win tough races in November.  

“We’ve endorsed Democratic candidates who reflect the values and interests of their states and who are best positioned to unseat Republican senators who have put politics ahead of the people they were elected to represent,” said Lauren Passalacqua, DSCC spokeswoman.

Could it backfire?

Their reasoning makes sense, especially in Florida, where Grayson faces a House Ethics Investigation over allegations he mixed his work as a congressman and hedge-fund manager. But the approach, which critics contend is reminiscent of the heavy-handed tactics used by party bosses decades ago, can also elicit backlash.  

The candidates who haven’t received endorsements have taken the snub in stride, saying it proves that they are aligned with the people instead party leaders. That kind of message has resonated with voters during the presidential primary for both parties, fueling the anti-establishment candidacies of both Donald Trump and Bernie Sanders.  

“With Bob Casey’s endorsement of my primary opponent today, it completes an all-inclusive rejection by Washington D.C.’s and Pennsylvania’s Democratic politicians of what I believe in, and stand for,” Sestak said after the senator announced his support of McGinty, according to The Morning Call .  

The DSCC’s endorsements have paid off so far. Strickland, Duckworth, and Ross each won their primaries easily, each earning more than 60 percent of the vote. The support for Murphy in his open-seat race against Grayson will boost his fundraising in a very expensive state, and Democratic leaders are confident their support and Grayson’s baggage will ensure victory.  

But in Pennsylvania, McGinty faces longer odds. Polls show her trailing Sestak four weeks before the primary, so far unable to overcome the former U.S. Navy admiral’s lingering goodwill among Democrats after winning the 2010 nomination.  

Sestak also has a history of toppling the Democratic establishment. In 2010, he defeated incumbent Sen. Arlen Specter in a primary despite the support of Casey, Obama, Biden, and the DSCC. Specter, who had switched from the GOP a year earlier, even featured Obama in a TV advertisement , which didn’t prevent him from losing by more than seven points.  

The ability for Democratic leaders to pick and choose favorites in Senate primaries stands in stark contrast to the GOP, which has had to abstain from endorsements in open-seat races after the tea party waves of 2010 and 2012 made establishment support a poison pill for candidates.  

The National Republican Senatorial Committee has not endorsed a non-incumbent candidate this cycle.  

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