Some point this autumn, there will be an election to the House of Representatives and for a little over half the Senate. One common feature in politics is the "honeymoon period" - that time when a new leader sees their party's support rise. And indeed, Labor support has risen. And it must be fortunate for Rudd that the general election could fall in his honeymoon period.
When Anthony Eden became Prime Minister in April 1955, he called a general election for just 7 weeks later, which saw the Conservatives and their allies (National Liberals, Scottish Unionist, Ulster Unionist) increase their share of the vote (to 49.74% - the highest ever for a post-war election) and MPs (although in October 1959, under Eden's successor, Harold Macmillan, they won more seats, but on a slightly lower share of the vote (this wasn't due to a Labour resurgence - the Labour vote fell - but the more-than-doubling of the Liberal vote).
With a free-floating election day, then an incoming Head of Government has the opportunity to put the election in their honeymoon period. With fixed terms, the reverse has to be done - move the honeymoon period to match the general election.
There are all these rumours about Conservative MPs wanting to oust David Cameron, the Prime Minister, as Conservative leader, and replace him with someone else. Ignore all these stalking horse stories - that is not how the leadership election works, as a sitting leader can only be removed in a no-confidence vote once enough Conservative MPs have written to the Chairman of the 1922 Committee to ask for one.
My advice would be to wait until autumn 2014. This would give the Liberal Democrats a reason for leaving and creating clear orange water between them and the Conservatives in the run-up to the May 2015 general election. It would give the incoming Prime Minister the chance to give the public a taster of what a single-party Conservative government under their leadership would do if they won an overall majority.
And it means the 2015 election could be in their honeymoon period, when the Conservatives are enjoying a bounce in the polls.
Another nation with fixed terms is the USA, with the elections for the President held on the Tuesday nearest to Guy Fawkes' Night in every year divisible by 4. No by-elections, no shifting the date. Regular as clockwork.
There are a couple of constitutional amendments which are significant. The first is the Twenty Second Amendment, which brings in term limits. Basically no-one can be elected more than twice to the Presidency, and in some circumstances (where they took over as President less than half-way through their predecessor's term) they are limited to being elected once.
The only Presidents it applied to - those who were elected twice since it was ratified - were Dwight Eisenhower (Republican, January 1953 to January 1961), Richard Nixon (Republican, January 1969 to resigning in August 1974), Ronald Reagan (Republican, January 1981 to January 1989), Bill Clinton (Democrat, January 1993 to January 2001), the younger George Bush (Republican, January 2001 to January 2009) and Barack Obama (Democrat, since January 2009).
In three of those cases, the sitting Vice-President won their party's nomination. Nixon was defeated by the Democrats' John Kennedy in November 1960. Reagan's Vice-President, the elder George Bush, was elected in November 1988, only to be defeated in November 1992 by Clinton. Clinton's Vice-President, Al Gore, was defeated by the younger Bush in November 2000.
As for November 2016, we have yet to see whether, at the nomination convention in August or September that year, the Democrats choose sitting Vice-President, Joe Biden, as their candidate.
If they do, then there is one way Obama can respond to the news - resign.
Not in disgust, or in anger, but due to the workings of another amendment - the Twenty Fifth Amendment. If Obama fails to complete his term of office, for whatever reason, then Biden replaces him. Not as Acting President, but as the constitutionally valid 45th President.
Hence, if that is the choice the Democrats make, then Obama's resignation in September 2016 would have Biden contesting the Presidential election in a unique position - an incumbent President still in his honeymoon period with the voters.
What I find interesting is that no second-term President has ever actually done that for their Vice-President.