U.S. Rep. John Tierney, a Salem Democrat who represents the North Shore’s Sixth District, holds the current fundraising advantage in a fall election race against Republican challenger Bill Hudak.According to the Center for Responsive Politics, a respected Washington, D.C. political watchdog, second-quarter campaign contributions through June 30 show Tierney so far has raised $561,694 in this cycle and spent $294,249 while Hudak has raised $487,987 and spent $361,753.Tierney’s big advantage is in the size of his war chest, monies collected but not used in his previous eight Congressional campaigns. Tierney has $1,550,056 cash on hand while first-time candidate Hudak, a former Saugus resident who now resides in Boxford, has only $126,234 in comparison.According to the Center for Responsive Politics, Tierney has collected 34 percent ($192,639) of his contributions from political action committees and 56 percent ($313,235) from individual donors and zero from self-financing.Hudak, on the other hand, has raised just $1,500 from PACs, $265,559 (54 percent) from individuals and has sunk $215,627 (44 percent) of his own money into the campaign.In an off-year election characterized as anti-incumbent, his huge war chest may serve Tierney well in a district where Democrat Attorney General Martha Coakley won just five municipalities – Bedford, Gloucester, Lynn, Newburyport and Rockport – out of 34 in the January special election against Sen. Scott Brown. Brown took 57.9 percent of the ballots cast while Coakley won just 41.2 percent.Lynn may be key to Tierney’s re-election bid as it had the lowest turnout for the district at 38 percent. Every other community had over 50-percent voter participation, so Tierney’s get-out-the-vote effort in the city looms as important.