By Nick Bryant BBC Washington correspondent

The Democrats would like the mid-term congressional elections to be a referendum on the Bush administration's handling of the economy.

For the White House, it makes sense to focus on Iraq.

History shows that Democrats do well when "pocket-book issues" dominate. Republicans prosper when national security tops the agenda.

Wednesday's speech by Al Gore - one of a number of recent appearances intended to signal that the presidency is still the target of his ambitions - has to be seen in that context.

'It's the economy, stupid'

This was his attempt to shift the focus to the economy - a call upon President George W Bush to devote as much attention to the nation's fragile economy as to regime change in Baghdad.

Bush has been trying to keep the focus on security and Iraq

It was also a pointed reminder to Democratic candidates around the country to tell voters "It's the economy, stupid" - the far-too-frequently quoted mantra of the Clinton/Gore 1992 campaign.

Mr Gore well remembers the lessons of '92, how the Democrats defeated George Bush Snr - a successful war-time leader, the victor of Gulf War I - by hammering home the message that he had neglected the economy.

Mr Gore hopes the same formula will work in the upcoming mid-term elections (even if a Texan billionaire named Ross Perot is not on hand this time round to help drive home the point).

Certainly, there is a wealth of statistics which will help Democrats make their case.

Unemployment stands at 5.7%, up from the 4.2% when Bush entered the White House.

Earlier this week, the stock market ended its worst quarter since the crash of 1987. And the typical household income fell for the first time in a decade.

'Corporate crime wave'

If people are hurting, the Democrats will say, then they should blame the White House.

Then there is the "corporate crime wave", involving companies such as Enron, with embarrassingly close links to the Bush White House.

Corporate malfeasance should help the Democrats, although voters seem to think that greedy chief executives are more to blame than the Republicans.

Inside the Beltway - the ring-road that encircles the nation's capital - there is a feeling that Iraq is dominating the election.

Step outside, and kitchen table issues are said to be high on the agenda.

The economy vs. Iraq - whichever issue comes out on top could decide the mid-terms.