Labour should turn to George Bush's Republican party for inspiration about how to boost party membership, Europe Minister Douglas Alexander has argued.
Can Labour learn from George Bush's campaign?
He said the success of the Republicans had been largely down to improved organisation and motivation.
But Work and Pensions Secretary David Blunkett warned the Republicans had also "built coalitions with extremely nasty people".
Labour's membership has fallen by 200,000 since Tony Blair took office.
The issue was the subject of a Guardian fringe debate, entitled "Winning back the missing voters" at Labour's annual conference in Brighton.
It is one of a number of initiatives the party hopes will address the problem of dwindling membership and low voter turnout at elections.
These include establishing a Labour Supporters Network - bringing onboard activists who back the party cause, but who do not want to be fully paid up members.
Elections Minister Harriet Harman is also introducing a bill to make it easier for voters to register.
In the debate, Mr Alexander told delegates it was possible for a "party in power to rejuvenate" itself.
He said Labour only needed to "look to the US and look at what the Republicans have done in office" for "inspiration".
The Republicans' success had been in "building a powerful movement", and by their use of emotive language, such as describing inheritance tax as a "death tax", he said.
"They have built that movement by organisation and motivation - that is why the language we use in politics matters," he said.
The challenge for Labour was not only to build on its successes in winning three general elections, but also to have a "candid conversation about what needs to be done" in Britain.
But Mr Blunkett said while he agreed the Republicans "have done a fantastic job", they had "gerrymandered" voting boundaries and "run rings round towns".
Ahead of the 2004 US election, Republicans in Texas redrew Congressional boundaries in such a way as to gain four additional safe seats, even though different boundaries had already been set out by the previous legislature.
Mr Blunkett said this was "the biggest fiddle that's going".
"They have got the language and they have built coalitions, but the thing that we have to realise - they have built coalitions of extremely nasty people and we can't do that," he said.
"We have got to build coalitions of people who want to do good, not just for themselves, but others - who want to tackle vested interests and, for some people, who just want a good life."
He said Labour's problem was that it often did not get the credit for its achievements, like building new sixth form colleges.
He said most people who did not vote "need a Labour government most".
And he warned that government ministers had to be careful they did not get so enmeshed in the minutiae of policy and the daily grind that they did not inspire other people to vote.
But Jane South, a delegate from Keighley CLP, said the Iraq war had "caused a massive haemorrhage of support" from Labour.
She called for the issue to be discussed.
"I'm a very loyal Labour Party member but I am also chair of my local peace group," she said.
"What I have seen is the support of the Labour Party go down and the peace group is flourishing and very active two years later."
Another delegate said: "I know at least 10 people who will vote Labour again - they will once Tony Blair steps down."