By Samuel P. Jacobs
WASHINGTON (Reuters) - Tuesday could be the final stop of Newt Gingrich's wild ride of a presidential campaign.
The Republican candidate told NBC News he would reassess his candidacy depending on his finish in Delaware, one of five northeastern states holding presidential primaries Tuesday, and the state where Gingrich has campaigned most heavily.
"I think we need to take a deep look at what we are doing," Gingrich told NBC in an interview on Monday.
Those comments came as Republican front-runner Mitt Romney visited New Hampshire, preparing to deliver what the former Massachusetts governor's aides are billing as his first address of the general election campaign against Democratic President Barack Obama.
A Gingrich spokesman did not immediately return a request for comment about the candidate's plans.
Despite a string of losses since his upset victory in South Carolina's Republican primary in January, Gingrich had vowed to stay in the race until his party's nominating convention in late August.
His withdrawal would clear the way for Romney to claim the unofficial mantle of the Republican nominee in November's election, putting to rest an often bitter primary campaign.
The only other candidate remaining in the race is a long shot libertarian, U.S. Representative Ron Paul of Texas.
The Gingrich campaign, in debt after struggling to counter an infusion of millions of dollars in so-called Super PAC money supporting Romney, has scheduled events this week in North Carolina, which holds its presidential primary on May 8.
Tuesday's primaries in Connecticut, Delaware, New York, Pennsylvania, and Rhode Island are the first since the departure of former U.S. Senator Rick Santorum, who was running second to Romney in the state-by-state nomination battle.
A weak showing for Gingrich, a former speaker of the U.S. House of Representatives, would be another blow to the candidate who fell behind Santorum as both vied to be the conservative alternative to Romney.
OUT OF LIMELIGHT, INTO DEBT
Gingrich, who rose to be the most powerful Republican in the United States during his leadership of the House in the 1990s, has finished first in two of the 31 states that have voted in the 2012 presidential contests.
The onetime front-runner has been largely out of media glare in recent weeks. His biggest headline came after an encounter with a biting penguin at the St. Louis Zoo left Gingrich with a bandaged finger.
More than any other presidential candidate, Gingrich has felt the impact of independent "Super PACs," the political action committees that have no limits on how much money they can raise or spend in support of candidates.
Throughout the primary season, Gingrich has depended on the largesse of a PAC called Winning Our Future, which has received at least $21.5 million in donations from billionaire casino mogul Sheldon Adelson and his family.
At the same time, a pro-Romney PAC, Restore Our Future, spent $19 million on ads attacking Gingrich.
In December, the former speaker led in the polls in Iowa, the first state to hold a nominating contest. But after a barrage of ads from Restore Our Future that cast Gingrich as a Washington insider with questionable ethics, he plummeted to a fourth-place finish in the Iowa caucuses on January 3.
Gingrich's campaign regrouped and captured South Carolina on January 21, but then was hit again by the pro-Romney group's attack ads before the next major primary, in Florida.
The former speaker's campaign has not recovered from that assault, and has been unable to keep raising enough money to cover its expenses. Last week's campaign finance filings with the Federal Election Commission showed $4.3 million in debt.
(Editing by David Lindsey and Doina Chiacu)