The official reason May gave for calling the poll is that Britain needs "certainty, stability and strong leadership" in its transition of leaving the EU, but is being opposed by "Remoaners" in Labour, Scotland, and the House of Lords.
The real reason is that she is confident, understandably, that she can win big.
Most surveys put the Conservatives 15-20 points ahead of a bitterly divided Labour Party, and the Conservatives will expect to secure a majority of over 100.
The obvious accusation is that holding a snap election, having spent months insisting that there was no need for one, is cynical party politics.
Still, if being self-interested and opportunistic were a crime, every politician would be in prison.
The Fixed-term Parliaments Act, means that May cannot call an election directly, but getting the support of two-thirds of MPs for a motion to hold a poll will be a formality.
The vote on 8 June will be the first general election in which EU relations will be a dominant issue. In fact, it will be a single-issue election for a single-issue government.
A decisive election win would give May a personal mandate to negotiate a tough or hard Brexit. Despite their dominance, the Conservatives only have a majority of 12 - it would only take a handful of rebel MPs for government to lose key EU-related votes.
A mandate and a big majority negates this threat and would kill off the prospect of Parliament rejecting the terms that May brings back from Brussels.
This would also kill off the idea of a second referendum on the terms of Brexit, and close down the argument that the electorate had not given consent to withdraw from the single market.
Whether voters will be happy with the economic effects of a hard Brexit and a return to World Trade Organisation terms with the EU will be a moot point. No one can say they were not warned.
Labour is trapped
Most opposition parties are happy to fight early elections. It is an earlier than expected chance to obtain power. For Labour, it is more likely a golden opportunity to lose another election.
The best that its beleaguered supporters can hope for is that a defeat would rid them of Jeremy Corbyn’s widely-derided leadership. Labour is polling at around 25 percent, and heading for its worst result in over 80 years.
A reluctant "Remainer", Corbyn will not want to talk about Europe. His reaction statement focused on the government’s economic record of "falling living standards and damaging cuts to our schools and NHS". These are worthy issues but they have not gained much traction with voters in the 20 months since he became party leader.
In short, Labour is trapped. Most of its MPs and party activists supported the Remain campaign and are bitterly disappointed by the result. Most of the seats it holds are constituencies where there was a majority Leave vote. Since the referendum, Labour has wrestled with this dilemma without resolving it.
By pitching herself so clearly as the prime minister for Brexit, May is also making a move to kill off the UK Independence Party (Ukip).
Ukip’s only MP, Douglas Carswell, left the party last month, while one of their Welsh Assembly members, Mark Reckless, defected to the Conservatives. Faced by a Conservative leader who has stolen their clothes, it is hard to see how Ukip can survive.
The 48-percent party
But not everybody will lose. An early poll is a golden opportunity for the Liberal Democrats to recover some of the lost ground from their near wipe-out in 2015, when they slumped from 57 to eight seats.
Their leader, Tim Farron, has positioned his team as the party of the "48 percent" - who voted to remain in the EU - and will expect to recover some of their lost supporters.
If the election makes good sense for English party politics, it is hard to see that a June election will solve the looming constitutional crises in Scotland and Northern Ireland.
The Scottish National Party will expect to hold most, if not all, of the 56 seats out of 59 that they took in 2015.
Scotish leader Nicola Sturgeon’s vow to protect Scotland “from a Tory party which now sees the chance of grabbing control of government for many years to come and moving the UK further to the right” underscores the sense of separation between Tory England and Nationalist Scotland.
There is "no turning back" from Brexit, May said on Tuesday. For the foreseeable future, she is probably correct. The odds are stacked in favour of 8 June entrenching her one-party Brexit state.