With Republican candidate Donald Trump dominating Super Tuesday and building even more momentum ahead of the party's national convention in July, Republicans are waking up to the possibility that the tycoon could be their party's nominee - and possibly the nation's president come November.
South Carolina Senator Lindsey Graham, who dropped out of the presidential race in December, told broadcaster CNN on Wednesday that he would support Texas Senator Ted Cruz over Mr Trump, because the latter is an "interloper" whom he does not trust.
Meanwhile, the party's 2012 nominee Mitt Romney has stepped up his criticism of Mr Trump in recent days and was to make a speech on the "state of the 2016 presidential race" yesterday, when he was expected to raise further questions about Mr Trump's electability.
Analysts suggest that Mr Trump is picking up many working-class voters, which may pose a threat to the campaign of Democratic candidate Hillary Clinton, as she too is jousting for the support of the working class. He has also been able to fuel voter turnout at the primaries, which may be the key to beating the Democrats in the general election.
"Given the uniqueness of this particular campaign cycle, I'm saying that anything can happen," said Associate Professor Daniel Franklin, a political scientist at Georgia State University.
While many point out that campaigning for the general polls has technically not begun, others say primary voters and contributors are already considering the electability of their candidates.
While Trump has shown a propensity to get new voters out to the polls, this probably isn't going to be enough for him to be electable in November, as I don't see many independents breaking his way.
POLITICAL SCIENCE ASSISTANT PROFESSOR JACOB NEIHEISEL
"Most of the contributions in political campaigns are what I call strategic, meaning that they are intended to support a winner. Trump is electable, particularly if he is backed by a united Republican Party," said Prof Franklin.
An average of recent polls done by political website RealClearPolitics shows Mrs Clinton would beat Mr Trump by 45.4 per cent to 42 per cent in a general election.
Also, what matters in making a candidate electable is whether the eventual nominee can swing independents and bring new voters into the fold, said political science Assistant Professor Jacob Neiheisel from the University of Buffalo.
"While Trump has shown a propensity to get new voters out to the polls, this probably isn't going to be enough for him to be electable in November, as I don't see many independents breaking his way," he said.
As for the other Republican hopefuls, former Ohio governor John Kasich's candidacy hangs in the balance due to his poor performance on Tuesday - when 11 states voted - while retired paediatric surgeon Ben Carson has signalled the end of his campaign, leaving only Florida Senator Marco Rubio and Mr Cruz.
To date, Mr Rubio has won only one of 15 states, while experts say Mr Cruz's strategy of counting on conservative voters has not panned out. Said Republican pollster Kristen Soltis Anderson: "In a general election, I suspect Ted Cruz would struggle a lot." She explained that he is banking on the "missing white voters theory", an estimated seven million who stayed home during the last election in 2012 because they found Mr Romney uninspiring.
"Ted Cruz believes that the way to get these voters to turn out is to... give someone a pure conservative to vote for," said Ms Anderson, adding that those voters he is targeting are "actually just the type of voter that likes Donald Trump" .
As for Mr Rubio, the deck appears stacked against him. "Rubio still has a fighting chance as we move into the winner-takes-all phase of the Republican primary, but he needs to perform very well in the big states, where there are lots of delegates at stake," said Prof Neiheisel.
Said Dr James Henson, director of the Texas Politics Project at the University of Texas: "In a world before Donald Trump demonstrated his political appeal and his political abilities, I think we would have pretty easily concluded that Marco Rubio was probably the candidate with the best chances in a general election, but Trump has demonstrated strength in a way that I am not sure we can so easily conclude that yet."