WE HAVE one immediate and obvious way to measure the Aintree effect. Nine days ago Dr Mo Mowlam said there was a "high possibility" that Sinn Fein could join the multi party talks on June 3rd, if the IRA immediately restored its ceasefire and honoured it "by word and deed" in the interim.
She would not, could not, repeat that suggestion yesterday.
Indeed, the Shadow Northern Ireland Secretary was barely to be heard, as more senior figures in Labour's high command denounced the IRA and slammed the door in Sinn Fein's face.
Reflecting the nationwide anger at the enforced postponement of the Grand National, Mr Tony Blair branded the IRA campaign "contemptible" and declared: "They must understand that they can never blackmail the British people with violence or the threat of violence."
But it was left to Mr Jack Straw, the Shadow Home Secretary, to spell out the practical political consequences. Mr Straw said the IRA had "put themselves beyond the pale as far as any resumption of talks with them in the short time after the election is concerned."
Mr Straw's prominence in leading the Labour attack stirred the first speculation in press circles about Dr Mowlam's own position. Was she being hung out to dry? Had she gone too far with her speculation about the possible time frame for Sinn Fein's admission to talks, and thus embarrassed the leadership?
You can never be sure what moves are afoot behind the scenes, especially in a party seemingly on the brink of power.
Northern Ireland, like Scotland, invariably spells political trouble. One fancies Mr Blair's inner circle of advisers and spin doctors was less than thrilled by headlines suggesting Labour enthusiasm for the revival of the "peace process" at this stage. They would surely be content to hear nothing at all from the Celtic fringes this side of polling day.
But their sensitivities and anxieties apart, sources insist there is no reason why Dr Mowlam's original comments would have fallen foul of the leadership. Whatever nods, winks and hints people may have discerned, she did not actually depart from a previously declared position.
While Mr Michael Portillo and a couple of Conservative backbenchers tried to make some capital, neither Mr John Major nor Sir Patrick Mayhew felt able to criticise her. They had allowed the very possibility of which she spoke.
She stuck firmly by the Conservative government's line in making clear that her judgment, as a Secretary of State, would rely on the words and deeds of the republican movement. She spelt out the specifics of that, telling republicans they would be required to end surveillance, targeting and the movement of weapons.
And it is always prudent to bear in mind that, should she get the job, Secretary of State Mowlam would make that final judgment in the light of advice from her security advisers.
The embarrassment, if such there was, would have been caused by people reacting to what they hoped, or wanted to believe, Dr Mowlam had said, as opposed to what she did say. Nowhere is this tendency more explicit than in Senator Edward Kennedy's renewed call in this newspaper for the renewal of the IRA ceasefire.
Senator Kennedy says Dr Mowlam "indicated that Sinn Fein would be admitted into talks on June 3rd if the ceasefire is immediately restored." The crucial distinction between "would" and "could" obviously did not carry well across the Atlantic.
Dr Mowlam has clearly been anxious to persuade people of her genuine desire for a fully inclusive process. She obviously believes there are some in the republican leadership battling to bring the IRA campaign finally to an end.
If they prevail, she would cheerfully tackle the hazardous business of bringing Sinn Fein in from the political cold while persuading the unionists not to take their place.
But she has not met republican demands for a fixed date for Sinn Fein entry, or for a fixed timeframe for the negotiation process. In putting it up to the republican leadership last weekend, the shadow Northern Ireland Secretary left herself plenty of escape routes.
And this weekend's events, following a week of sustained disruption and chaos, have provided a nervous Labour leadership with the easiest exit of all.
The eternal optimist will put all this down to the necessities of an election campaign, and expect everything will prove very different come May 2nd. Indeed, nothing definitive can be forecast until the British and Irish elections are both out of the way, and the republican leadership finally comes to a decision.
No British government, of either complexion, will declare Sinn Fein permanently excluded from the political process. Mr Major yesterday stated the obvious when he said the IRA had put back the date when Sinn Fein might join.
The government in waiting sees the republican movement as split, with the "militarists" currently in the ascendant. If the pendulum swings the other way, and translates into a second ceasefire, a Labour government would assuredly want to test it (so to speak) to destruction.
But as one senior Labour source put it last night, "the test grows harder all the time." The potential timescale of just a week ago now seems to have been foreclosed.
Sinn Fein should study Mr Blair very carefully. If he wins the election, he will consider it imperative to be seen to be tough on terrorism - and not to be seen as suckered by easy and empty promises.