It is all or nothing for Irish American presidential candidate Martin O’Malley in tonight’s presidential debate against Hillary Clinton, Bernie Sanders, Jim Webb and Lincoln Chafee.

The 52-year-old O'Malley, who traces his roots to Galway and Mayo, is a former Baltimore mayor and Maryland governor and was considered a viable outsider before entering the race.

Young, dynamic, good looking, and smart with a Kennedyesque air, many felt he would line up as the biggest opposition to Hillary Clinton in the primaries.

However, that role has fallen instead to Bernie Sanders, the 74-year-old fiery left-winger, who has grabbed the torch for those to the left of Clinton.

As a result, O’Malley has been pretty much ignored in the race up to now as the media have turned it into a two horse race between Sanders and Clinton.

O’Malley wasn't helped when his entry into the race coincided with deadly riots in his home city of Baltimore. He canceled his schedule in Ireland to fly back and try to help but questions about why the riots happened dogged him.

As a result he has struggled, even though by most accounts he has done very well connecting with Iowa and New Hampshire voters on an individual basis. Many experts express surprise he is not polling better as a result.

That is why O’Malley needs to strike during the first debate.

He told the Washington Post just that:

“I feel like the campaign really begins on Oct. 13 in a lot of ways,” O’Malley said.

“It’s malpractice as a party to have waited so long to begin our debates. Eight years ago, we had already had nine debates. But now we’ll finally have our first, and finally we’ll get the opportunity to make our case to the American people.”

Experts agree. "This is it. This is his chance," Mo Elleithee, a longtime Democratic strategist who is now director of the Institute of Politics and Public Service at Georgetown University told the Baltimore Sun.

"If he does not seize the opportunity to break through in this debate, then I think he's going to have to take a step back and figure out a new rationale for his candidacy."

O'Malley will be conscious that contenders like Donald Trump and Carly FIorina used the GOP debates as their launching pads to break through widespread media cynicism about their candidacies.

Almost forgotten now is Trump’s campaign launch where he was accused of paying people to come and cheer it at Trump Tower.

Florina started off in the kiddy pool debate, not even on the main stage, yet has now vaulted into the top threee after strong debate performances.

O’Malley will be hoping for a similar rub of the green. The media will also be focused on the man who is not there, Joe Biden and his intentions, so O’Malley will have to hit a home run to become relevant.

He has several aspects on his side: his youth in contrast to Hillary who is 67 and Sanders 74, his experience as a popular mayor and governor and his willingness to challenge the status quo and the near reverence in which Hillary is held by many primary voters.

In his spare time O’Malley fronts a band called “O’Malley’s March “ which plays the DC circuit. He will be hoping for a forward march after Tuesday night.

There is certainly no more Irish candidate in the race. I got to know him during the Clinton visits to Ireland when Bill was president. He displayed a knowledge and depth far greater than the usual Irish American pol’s blather when talking about the old country.

Now it remains to be seen if he can move up the ladder. Remember Joe Biden got little more than 1 percent in Iowa and ended up Vice President. O’Malley is looking at similarly long odds, but he has defied those in the past.

Tuesday night will be the test.

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Former Maryland governor Martin O'Malley pledged support for immigration reform and spoke of the importance of his Irish roots.iStock