With the U.S. Capitol as backdrop and some campaign posters slapped on a podium, Rob Sobhani delivered the closing statement for his party-crashing campaign in Maryland’s U.S. Senate race.

Two reporters attended.

Sobhani, a Montgomery County businessman who has poured more than $6 million of his own fortune into the race, said Thursday that he believes his campaign has tapped widespread discontent with the two major parties and could inspire more voters to back outsiders like him.

“I started this race a few months ago as an independent because I believe the political system we have today is not working for the American people,” Sobhani said, two days after Hurricane Sandy forced Salisbury University to call off a debate that would have put him on the same stage with Sen. Benjamin L. Cardin (D) and Republican challenger Daniel Bongino. Sobhani said his campaign would give Marylanders “a real choice.”

Polls suggest, however, that Sobhani’s entry into the race has all but guaranteed that Cardin will coast to victory and the Democratic Party’s hold on the one-party state will stay that much tighter. At least some of Sobhani’s support has come from voters who might otherwise back Bongino, a former Secret Service agent in his first run for office.

This week, The Baltimore Sun reported that a poll by OpinionWorks found that half of the likely voters who responded backed Cardin. Bongino won 24 percent, and Sobhani received 14 percent. The poll found that one in 10 voters was undecided, the Sun said.

A Washington Post poll last month gave Cardin 53 percent of the vote among likely voters. Bongino and Sobhani split the rest with 14 percent and 22 percent, respectively.

Even an internal poll by Sobhani’s campaign shows Cardin with a comfortable plurality. The campaign-sponsored poll, conducted in October with 1,800 respondents, showed Cardin with 35.5 percent, Sobhani with 20 percent, and Bongino with 16.5 percent. After further analyzing undecided voters’ leanings in the poll, the Sobhani campaign said Cardin’s lead narrowed and Sobhani’s support grew. But Cardin still won 44.6 percent versus Sobhani’s 34.5 percent. Bongino had 20.8 percent, according to the Sobhani poll.

Sobhani — who ran for Senate twice before in GOP primaries — shrugged off a question about whether his entry in the campaign has meant the Democratic Party could hold the seat without a sweat.

“I think my race is a question of principle,” Sobhani said. “I’m doing this because I truly believe that both parties have let America down.”

Sobhani, who entered the race in September, has poured about $2.5 million into TV ads that brought a measure of recognition as he pushed for a debate with the major-party candidates. Last week, Cardin, Bongino and Sobhani mixed it up for the first time — along with Libertarian Party candidate Dean Ahmad — in a radio studio for Larry Young’s Morning Show on WOLB in Baltimore. Then Hurricane Sandy prevented a rematch on the Eastern Shore at Salisbury University.

“It was very unfortunate that we didn’t get a chance to debate,” Sobhani said, noting that this year’s presidential debates between President Obama and former Massachusetts Gov. Mitt Romney had altered the dynamics of that race.

Sobhani said he still had a chance to beat Cardin.

“He may be polling well, but I believe there’s still a lot of people undecided in this race,” Sobhani said.

Sobhani also said he had no regrets over investing at least $6.5 million of his own money, including a loan to the campaign of $1.6 million reported in the latest two-week period covered by the Federal Election Commission.

“You have to have skin in the game,” Sobhani said.

In the same two-week period through Oct. 17, Bongino raised $262,342 for a total of about $1.2 million in the current cycle. Cardin raised less in the most recent period but still leads with a haul of more than $5 million. By contrast, Sobhani raised $3,890.