Former Pennsylvania Rep. Joe Sestak formally launched his long-expected challenge to Republican Sen. Patrick J. Toomey Wednesday, setting up a possible rematch in one of Democrats’ best pick-up opportunities .  

During an announcement outside Independence Hall in Philadelphia, Sestak said he is running to “restore the trust deficit,” according to the Philadelphia Inquirer . After showing up in a pair of old sneakers, Sestak vowed to walk across the state in a pair of Army boots — to walk symbolically in the shoes of Pennsylvanians.  

The former Navy admiral served two terms in the House before seeking the Senate seat in 2010. He defeated then-Sen. Arlen Specter — who had switched parties a year earlier — in the Democratic primary before losing to Toomey by just 2 points in a dismal election cycle for Democrats nationwide.  

Sestak is the front-runner to win the Democratic nomination in 2016, but he could face a primary and his announcement event had a couple hiccups. The Youtube livestream promoted by his campaign wasn’t functional, and his website was “down for scheduled maintenance.”  

Since losing to Toomey in 2010, Sestak continued traveling the state to meet with voters and announced in May 2013 he was exploring another bid. He ended 2014 with nearly $1.6 million in the bank.  

Democrats expect competition for the nomination, but it’s unclear who will step up — and if any would have the money or familiarity with voters to win the nomination. Former Rep. Chris Carney, state Sen. Vincent Hughes and Philadelphia District Attorney R. Seth Williams have all been floated as possible contenders, but none have made moves to launch bids.  

Looking to net five seats to ensure control of the Senate, Democrats will heavily target Toomey in 2016. President Barack Obama carried the state in both 2008 and 2012 by 11-point and 5-point margins, respectively.  

Toomey has been banking campaign cash in preparation for a tough re-election. He ended 2014 with more than $5.8 million in cash on hand.  

The race is rated Tilts Republican by the Rothenberg & Gonzales Political Report/Roll Call.  

Related:

Pat Toomey Is a Strong Candidate. Will That Be Enough in 2016?


Russ Feingold, Joe Sestak and the Improbable Senate Race Rematch


Pennsylvania Democrats Hesitate on Sestak Senate Bid


10 Races to Watch in 2016: Pennsylvania Senate


The 114th: CQ Roll Call’s Guide to the New Congress


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