WASHINGTON - Two years after a tea-party wave swept the nation and helped Republicans flip three swing seats in the Philadelphia region, local Democrats hope Congress' rightward tilt works in their favor this Election Day.

In moderate suburban congressional districts, Democrats are working feverishly to pin incumbent Republicans to votes backing the conservative agenda pushed by the House majority in power since the 2010 elections. The suburbs' middle-of-the-road voters did not bargain for the Republican plans on Medicare, taxes, and women's health, the challengers argue, echoing the case made by Democrats in moderate districts around the nation.

"The buyers' remorse that has set in against Republican tea-party incumbents is strong and deep," contends Rep. Steve Israel of New York, chairman of the Democratic Congressional Campaign Committee. "They are fighting an uphill battle."

With that message fueling their campaigns, Democrats have put four local races on their list of top priorities.

Republicans counter that they remain the trusted party on the most important issues in the election: jobs and the economy. "People have to look and see which party has the more effective plan on leading Americans back to prosperity," said Vince Galko, a Republican consultant who has worked on many campaigns in Southeastern Pennsylvania. "The plan but also the actions taken by the Republican caucus in the House prove that they're the right choice."

The competing arguments will arrive prominently via television screens and mailboxes in the coming weeks as the two sides sprint toward Nov. 6.

Democrats need to gain 25 seats to take back control of the House, a crucial prize in steering national debates on debt, taxes, spending, and entitlement programs such as Medicare.

Four Republican incumbents in the region are on Democrats' "Red to Blue" list of top national targets: Mike Fitzpatrick, Jim Gerlach, and Patrick Meehan in Pennsylvania, and Jon Runyan in New Jersey.

Some of those races promise to be tighter than others.

Political analysts and operatives from both parties say Democrats' best chance for a pickup locally is in the Bucks-based Eighth District, where the GOP's Fitzpatrick is defending his seat against lawyer Kathy Boockvar.

Fitzpatrick is emblematic of his district's mercurial nature: He won the seat in 2004, lost it two years later, and returned in 2010 with the help of the Independence Hall Tea Party.

Runyan, the ex-Eagles football player who is a House freshman in South Jersey's Third District, faces a tough challenge from Shelley Adler, a former Cherry Hill councilwoman and widow of former Congressman John Adler.

Manan Trivedi, a Navy doctor who served in Iraq, is taking a second run at Gerlach in the Chester County-centered Sixth District. George Badey, chair of the Radnor Democratic Committee, faces Meehan in the Delaware County-based Seventh. Democrats in those campaigns face steep odds, according to party insiders.

Maps and money. In large part, that is because those races reflect two overarching obstacles for the region's Democrats: GOP-led redistricting has tilted the playing field, and Republicans hold commanding leads in fund-raising.

After the decennial changes in the congressional map, some analysts say it may be years before Democrats can retake what were historically swing districts. (Fitzpatrick's is an exception; its demographics still lean slightly Democratic.)

"The efforts at drawing those congressional lines diminishes what would otherwise be some of the most competitive areas in the country," said Chris Borick, a political science professor at Muhlenberg College.

In the remapping, districts "were made considerably safer for Republicans, and that trumps almost everything in what we call a non-wave election," said Terry Madonna, a political scientist at Franklin and Marshall College.

Some fretful Democrats point to Gerlach's consistent ability to withstand challenges and former Rep. Joe Sestak's decision not to challenge Meehan, leaving the party with the lesser-known Badey.

Democratic campaign officials insist the seats are within reach. They say that even with the new shapes, it is territory where President Obama won in 2008, and they hope to ride his coattails this year.

The challengers have highlighted Republicans' votes to overhaul Medicare, a plan vaulted into the national spotlight when its author, Paul Ryan, became GOP presidential nominee Mitt Romney's running mate. "Paul Ryan has become a down-ballot disaster" for Republicans elected to Congress in 2010, Israel said. "They got swept in on a tea-party tsunami, the wave has receded, and they are left high and dry with their voting records."

Voters can also expect to hear a heavy dose of campaigning on the GOP's votes to strip support from Planned Parenthood and restrict federal funding for abortions. Galko, who is advising Gerlach, says that unpopular Democratic policies, not just the tea party, drove Republicans' 2010 victories and that voters will be loath to turn back to Democrats. "If you look at where these seats are that we picked up, it had a lot to do with the failed policies of this administration and the failed policies of Nancy Pelosi and Harry Reid," Galko said, referring to Democratic leaders in the House and Senate.

Republicans have said their Medicare votes will preserve the program for the future and attacked Obama's plans to find savings in Medicare. "The only down-ballot disaster in House races is Obamacare and its $716 billion in Medicare cuts for current seniors," said a National Republican Congressional Committee spokesman, Nat Sillin. (Republicans count on the same savings in their budget, but not for the health-care plan Obama pushed.)

So far, local GOP incumbents have generally had a less unified message and done less public campaigning than their challengers. They have largely focused on raising questions about their opponents' backgrounds.

The Democratic candidates lack voting records to defend, but they are less well-known, giving the GOP an opening to attack their credentials.

In redistricting, Gerlach got one of the biggest demographic boosts - and he was already someone Democrats had repeatedly targeted but failed to take out. He beat Trivedi in 2010 by 14 points; now they face off again, in a more Republican district. Meehan also was helped by the mapmakers. His more Republican district now sprawls through five counties.

The new maps made Runyan's district in South Jersey only slightly more Republican, but one change could make a big difference. Cherry Hill - a Democratic stronghold and Adler's natural base - was cut out, replaced by more far-flung Democratic areas.

House candidates will have to rely largely on paid advertising to deliver their messages, and Republicans have far more money available for that battle.

Trivedi, Adler, and Boockvar are doing well for challengers, but recent reports showed each had raised less than half what their opponents had taken in. Badey had raised $316,000 compared with Meehan's $2 million. Elsewhere, Philadelphia and its environs are all but certain to reelect Democrats Bob Brady, Chaka Fattah, and Allyson Schwartz. In New Jersey, Camden County Democrat Rob Andrews, Ocean County Republican Frank LoBiondo, and the GOP's Burlington County congressman, Chris Smith, are seen as similar locks.

Contact Jonathan Tamari