Melissa Sim U.S. Correspondent In Washington

A waiting game before bids are announced

All the pieces are in place and everyone already assumes they are going to be running for the 2016 presidential election - so what are former Florida governor Jeb Bush and former secretary of state Hillary Clinton waiting for exactly?

This week, Republican Senator Ted Cruz already announced he is running for president, officially becoming the first entrant to the 2016 presidential race, but Mrs Clinton and Mr Bush - seen as the front runners of their respective parties - have not followed suit.

By this time in 2007, in the lead-up to the 2008 election, Mrs Clinton and President Barack Obama had already officially thrown their hats in the ring. Yet this year, candidates are being coy about their intentions to run for president - doing everything to indicate their interest but avoiding the official declaration.

None of this has anything to do with indecision, though.

Chances are, everyone who wants to run for president has already made up his mind by now. As it turns out, there are other reasons - strategic and logistic - to at least pretend they are still thinking it over.

Among the prospective candidates, Mrs Clinton has lived in the in-between world of "uncandidacy" the longest.

The former secretary of state was duly vague last September when she said she would "make a decision... probably after the first of the year".

Till now, she has all but made an official bid for the Democratic nomination, and pundits are toggling between an April or July announcement, with some wondering if Mrs Clinton will stretch it till October - which is what her husband, former president Bill Clinton, did for his 1992 presidential campaign.

The last time Mrs Clinton ran against Mr Obama for the democratic nominations, she made the announcement in January, through a video statement released on her website.

Mr Obama followed soon after, officially announcing his candidacy for the White House in February to a crowd in Springfield, Illinois. That year, Republican nominee for president John McCain formally put in his bid in April.

One big reason candidates in recent elections like to take their time is that it gives them more freedom to raise money. In fact, thanks to the increasing importance of entities called super political action committees, or super PACs, it is even less likely that candidates would jump in early.

A super PAC, which was introduced in 2010 after several landmark Supreme Court rulings, is a group that can accept unlimited donations from individuals, corporations and other groups to use for political campaigns. Every presidential candidate at the next election will have one supporting them.

They are set up to support White House contenders but the group must act independently and is not allowed to coordinate with candidates. Candidates cannot help them raise funds and they cannot coordinate with candidates on what sort of ads to run.

These limitations do not apply, however, to anyone who has not officially declared their candidacy. So many looking to build up their election war chest will want to campaign for their super PACs for as long as possible.

Mr Bush, for example, has been flying across the country attending fund-raisers for the super PAC Right to Rise, which is on track to raise tens of millions by the end of this month. There are predictions that more than US$2 billion (S$2.7 billion) will be spent by super PACs on the upcoming presidential election.

Mr Cruz, however, is a federally elected official, and under campaign finance rules, he could not set up his own super PAC and already faced fund-raising limits, so in this respect, there was no incentive to delay his announcement.

For Mrs Clinton, the concern is not so much about raising money, as she already has a bevy of donors that she can count on. Instead, e-mail scandal notwithstanding, there are other strategic advantages to a delay.

Many donors are waiting to see what Mrs Clinton does before they support any other Democratic candidate, so holding back on an official announcement would actually stunt fellow Democratic competitors' ability to move forward with their campaigns, and limit their ability to raise funds, thus increasing her chances of winning the Democratic nomination.

While that may not seem necessary for the party front runner, one should not forget that she was in a similar position in the run-up to the 2008 presidential campaign, but was later overshadowed by Mr Obama.

A longer campaign also means two things for any candidate. First, more staff members and more travel over a longer campaign duration would incur higher expenditure. Second, the longer the campaign period, the more attacks from across the aisle in Congress.

Despite her "uncandidacy", Mrs Clinton is already being targeted. For example, Republicans criticised her for using her own private e-mail account while she was secretary of state, questioning her lack of transparency.

But an official announcement would truly put her under the microscope. She would also have to weigh in on issues such as the Islamic State in Iraq and Syria, as well as Iran, which she can still avoid doing under the cover of her "uncandidacy".

There are, of course, risks attached to waiting.

It may signal to voters that a prospective candidate is unsure of whether he or she wants to be president, or in Mrs Clinton's case, indicate a sense of over-confidence that she does not need to campaign to win.

But an earlier declaration might equip her with the political apparatus to deal more effectively with problems as they surface.

There seems to be a sweet spot between announcing too soon and waiting too long.

A Bloomberg analysis shows that since 1972, presidential winners have announced their candidacy an average of 492 days before the general election.

In years where there are no incumbents, which is the case for the upcoming election, the announcement comes earlier - an average of 511 days (about 17 months) before the election.

These trends suggest that a winning candidate would make an announcement some time around June this year. However, the way this campaign is going, that is far from guaranteed.