There's little doubt that Mitt Romney will be the Republican presidential nominee, as he faces not much more than token opposition since his main rival, former Pennsylvania Sen. Rick Santorum, dropped out of the race. But the former Massachusetts governor still has to amass the delegates needed to officially clinch the nomination and his quest continues Tuesday when GOP voters in Connecticut, Delaware, New York, Pennsylvania and Rhode Island weigh in.
It's a friendly region for Romney, with relatively few of the evangelical Christian and mostly social conservative Republican voters that he has struggled to win over during the primary campaign. Most political observers expect he will win the contests by wide margins as the party coalesces behind him as their standard-bearer.
But detractors will also be closely watching Tuesday's results to see if there continues to be discomfort within the party for Romney.
Pennsylvania, which was widely expected to be the closest of the five primaries until Santorum dropped out, could still prove to be his weakest showing. In addition to potential for sentimental Santorum votes, the Keystone State features a wide swath of rust belt voters—similar to Midwest states Ohio and Michigan—where Romney had to fight hard for victories.
And while Romney's successful business career is a plus for many voters who hope he will bring a CEO's sensibility to the White House, it's also been hard for the multimillionaire to connect with working class voters. His ability to do so in the remaining primary contests will likely impact whether or not he can deny President Obama of being re-elected.
Pennsylvania is also one of a handful of swing states expected to determine the presidency in the fall and while Romney's primary performance will not be a direct indicator of how all Pennsylvanians feel about him, it should provide an indication for how excited his base is.
Meanwhile, Romney still does face competition from two opponents, former House Speaker Newt Gingrich and Texas Rep. Ron Paul.
Paul, who has proven more adept at maintaining a solid level of fundraising throughout the long primary slog than his competitors, has yet to secure victory in any primary or caucus held up to this point. But that doesn't mean he's giving up – the libertarian still has strong support among young voters and has focused most of his campaigning in Rhode Island.
Gingrich has spent time in Delaware, with his campaign continuing to roll out endorsements of local politicians over the last week. But the former speaker's campaign is in deep debt according to the most recent federal campaign finance reports, and he has failed to mount any serious advertising efforts.
Even if Gingrich or Paul were to pull off upset victories, the two states they've targeted would result in a mere handful of delegates when compared to New York and Pennsylvania.
So Tuesday's key for Romney will be not whether or not he wins the five contests, but how much he wins them by and which voting demographics he shows improvements in. If he can meet the about 70 percent support threshold—the winning margin both John McCain and George W. Bush established in prior primary contests following their informal securing of the GOP nomination—the Romney campaign will likely be very pleased. As well, if he can show improvement with groups such as social conservatives, working class voters and voters without college degrees, it would be a sign that in addition to the GOP establishment, the party's voting base is ready to accept him.