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Newt Gingrich plans to "reassess" his campaign after Tuesday's Republican primaries, his daughter said, in the latest sign the former House speaker may be considering an exit from the race.

Voters in five states are heading to the polls Tuesday. The contests were initially expected to be a decisive showdown between Mitt Romney and Rick Santorum, but Santorum's decision to suspend his campaign effectively handed the nomination to Romney.

Romney could shut out his remaining rivals with a strong performance Tuesday night.

Jackie Gingrich Cushman said Tuesday that her father's campaign has slimmed down but is still winning over voters who aren't yet sold on Romney. Speaking on MSNBC, she said her father is awaiting the results of the primary in Delaware. The other primaries are being held in New York, Pennsylvania, Rhode Island and Connecticut, states thought to be friendly territory for former Massachusetts governor Romney.

Despite trailing Romney in convention delegates and fundraising, Gingrich has vowed to campaign until the party's late-summer convention in Florida. Gingrich is carrying more than $4.3 million in debt and has been spending more money than he is taking in.

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The low-key race on Tuesday could set the field for the general election.

On the Democratic side, President Obama is expected to formally clinch his nomination on Tuesday -- achieving the needed 2,778 delegates by the time polls close Tuesday night. Not that there was ever any doubt, as the Democratic primary was uncontested.

On the Republican side, Romney has the opportunity Tuesday to sideline both Gingrich and Ron Paul. While Romney will not be able to clinch the nomination outright -- he needs 1,144 delegates to do that, and will not reach that threshold Tuesday -- he could make it mathematically impossible in most scenarios for either of his two remaining opponents to reach that number.

If both Paul and Gingrich perform poorly on Tuesday night, the number of delegates they each need to pick up to reach 1,144 will exceed the number left on the table, based on numbers in the Associated Press tally.

Asked for comment on the looming contests, the Gingrich campaign on Monday gave no indication it was considering an exit from the race.

"Gingrich is conservatives' last hope in this primary. He remains committed to the conservative cause and this election," spokesman R.C. Hammond said.

The Gingrich campaign hopes the delegate numbers reported in the AP tally are fluid -- the campaign, for instance, challenges the awarding of all Florida's and Arizona's delegates to Romney despite their violation of party rules in holding early elections.

The Gingrich campaign has also predicted it will do well in at least one of Tuesday's contests -- the primary in Delaware. The other primaries are being held in New York, Pennsylvania, Rhode Island and Connecticut, states thought to be friendly territory for former Massachusetts governor Romney.

A total of 209 delegates are at stake.

The latest AP tally puts Romney at 697 delegates, Gingrich at 137 and Paul at 67. Santorum had 269 delegates before he suspended his campaign.

Romney has long been campaigning as a de facto general election candidate, focusing his stump speeches on Obama. He was glossing over his rivals even before Santorum dropped out.

Gingrich, though, has continued to campaign. Despite a communication glitch that resulted in reports over the weekend that he was canceling a planned North Carolina trip, the campaign released a schedule on Saturday showing Newt and Callista Gingrich blanketing the state through the end of this week. North Carolina holds its primary May 8.

The Associated Press contributed to this report.