Washington — While the brawl for the open 5^th Congressional District seat is considered the marquee race for the House of Representatives in Connecticut this year, another congressional contest is gearing up to compete for attention.

Rep. Jim Himes, D-4^th District, is defending himself from Republican Steve Obsitnik in a race that’s becoming increasingly heated. Attacks are now limited to mailings, press releases and campaign stops, but they are expected to migrate to television once the candidates begin spending money on cable ads.

Both candidates are trying to rally the base of their party and to also lure the support of  independents, who make up more than 40 percent of the voters in the 4^th District.

That strategy is sometimes a difficult balancing act.

Himes, who lives in Greenwich and has represented the Fairfield County district since 2009, is trying to link Obsitnik to House Republicans dominated by the conservative wing of their party.

“He would come here to be part of a (Republican) conference that wants to eliminate clean air and clean water regulations and cut food stamps,” Himes said.

Himes also attacks Obsitnik for not staking out positions on some issues, a strategy that’s espoused by many candidates who need the votes of both their party faithful and independents.

Himes himself has straddled some issues.

He voted last week against extending all Bush-era tax cuts set to expire at the end of the year. But two years ago Himes voted to extend those tax cuts.

He calls himself a moderate Democrat and has joined fiscal conservatives in his party by backing the implementation of a commission co-chaired by former Republican Sen. Alan Simpson and former Democratic White House Chief of Staff Erskine Bowles. The Simpson-Bowles commission called for tax increases on the rich, defense spending cuts and reforms to Medicare, Medicaid and Social Security. But Congress has largely ignored the politically sensitive Simpson-Bowles recommendations.

Himes has also bucked his party by voting for a GOP defense budget that would help Connecticut’s defense industry.

Obsitnik, meanwhile, is trying to tie Himes to the faltering economy, saying he’s backed Democratic policies, including the stimulus bill, that have misfired.

“If things were great, a person like me would not be running for Congress,” Obsitnik said.

Obstinik, of Westport, is the owner of a global technology firm, a decorated Naval officer and a graduate of the U.S. Naval Academy in Annapolis, Md.

He has distanced himself from the national GOP by refusing to call for a complete repeal of the Affordable Care Act, urging a major overhaul of the health care law instead.

A pro-choice candidate, Obsitnik has also broken with his party on social issues.

“Social issues are not the challenges or our time, the economy is,” he said.

District leans Democratic

Some of the issues raised in the 4^th District race are likely to be echoed in the 5^th District race once the Aug. 14 primary winnows the candidates for the general election from a crowded field. Right now, most of the energy in that race has centered on Democratic candidate Chris Donovan’s campaign scandal, but eventually the fight for independents will dominate the race in a district that, like the 4^th, leans Democratic.

That’s why Obsitnik has an uphill climb to wrest the 4^th District seat from Himes, said Gary Rose, chairman of the Department of Government and Politics at Sacred Heart University in Fairfield.

Voters in the 4^th District gave President Obama 60 percent of their support, and the march away from the GOP “has been slow but sure,” Rose said.

“Himes has also got the power of incumbency and his name recognition is higher,” Rose said.

Former Rep. Chris Shays, a Republican who is running for Senate, represented the district for years before being ousted by Himes in 2008.

Himes’ survival of the Republican wave of 2010 solidifies his position, said David Wasserman of the Cook Political Report.

“Himes won in 2010, the environment is better for Democrats now, and turnout will be up in Bridgeport,” Wasserman predicted.

But Rose said voters are still looking for a change.

“Obsitnik is coming in at a time when there is a lot of concern about politicians and the economy,” he said. “He’s an underdog, but he has very good credentials and he speaks well.”

Although he’s nowhere near the $2.2 million mark hit by Himes at the end of June, Obsitnik has also done well as a challenger in raising campaign money, about $726,000.

That has prompted the National Republican Campaign Committee to name Obsitnik a “Contender” — one rung away from “Young Gun” status — that would make his race a priority for the national party.

As November’s Election Day gets closer, SuperPACs may come into the race, perhaps making up for the gulf between the candidates’ fundraising.

In the end, Rose said the race “leans toward Himes.”

“But it’s not a sure thing,” he said.