The free-thinking Tory class of 2010 can be hard to pin down on the old wet versus dry, left to right spectrum. Stratford-upon-Avon MP Nadhim Zahawi took part in the traditionalist rebellion to wreck Lords reform. He is a keen supporter of deficit reduction, while being an enthusiast for Cameroonian "nudge". Now he has outflanked his colleagues as a migration liberal by proposing an "amnesty” for immigrants without legal status in a forthcoming essay for a new think-tank. His pitch is that it would send a dramatic signal to non-white voters that the Conservatives have changed, and would boost economic growth too.

Zahawi's proposal is essential advice for the US Republicans, who won't recover with Hispanic voters unless immigration reform passes, and they who won't win the Presidency again until they do, as Karl Rove warned his party last week. But the same policy won't be taken up by the British Conservatives, and nor would it work if it was. 

Indeed, conflating two important but distinct issues — winning ethnic minority votes, and dealing with undocumented migrants — could well make progress on either front a bit harder.

There is a strong sense of ethnic solidarity in the US between Hispanic citizens and 11 million who are undocumented. Settled minorities in the UK don’t identify with those without legal status. Ethnic minority voters in the UK may have a range of views on the 'amnesty' proposal. A minority will support it; most would have questions or concerns. Above all, most would be surprised – and bemused – if told that the policy was a special initiative designed to win their votes.

The more apt US analogy may be with black voters. Most African-Americans now support reforms including a path to citizenship for millions — as do two-thirds of all Americans — but it was hard work for campaigners to get there. Pitching this as the next step forward for the civil rights movement alienated US black people. It implied that their own status as citizens was still more provisional and less secure, than that of white Americans. What proved crucial for black voters, as with blue collar and trade union support, was to make enforcing minimum labour standards part of the deal when giving citizenship to the undocumented. This spoke to a shared interest: how preventing the exploitation of those without legal status could protect other workers from being undercut by rogue employers.

British political parties too often exaggerate the differences when talking about how to win non-white votes. Some talk about reaching out to 'immigrant communities'. As David Lammy told a recent cross-party Runnymede Trust seminar, there is still a tendency to talk about ethnic minorities "as if we have just come off the boat". That rankles with second and third generation Britons. The approaches to mobilise 'ethnic votes' that worked for their grandparents may increasingly fall flat with younger voters, born in Britain.

Here's the truth about ethnic minority voters: they are, mostly, very like white voters. Their top priority issues are jobs and the economy, education, the NHS and crime.
 
The one very striking difference between non-white and white voters is an unusually high level of identification and allegiance to Labour, and a corresponding distance or distrust of the Conservatives. This should concentrate Conservative minds, as Zahawi rightly argues. It doesn't arise from issue preferences. The other differences in attitudes are more nuanced. Ethnic minority voters don't particularly have more left-wing views: they turn out to be slightly more sceptical about tax and spend; a bit tougher on crime; more confident about race relations than white Britons, though a bit keener on integration too, with more confidence in the political system, and with a somewhat stronger sense of British identity too. The core concerns of ethnic minority voters are widely shared.
 
What about immigration? Non-white voters also worry about the scale of immigration, but polls show it is a lower priority than for white voters. Minority concerns more often reflect economic rather than cultural anxieties. There is more sympathy for asylum seekers among most minority groups, though not among British Indians.

Still, the Conservatives could damage their electoral prospects among minority voters over immigration. The proposal for a £3000 visitors bond, strongly criticised by the Financial Times for undoing the good work of David Cameron's trade mission to India, would have been unpopular at home too. That it was proposed for India, Pakistan, Sri Lanka, Bangladesh and Nigeria, but not Australia, New Zealand or Canada, meant it was quickly criticised as discriminatory.
 
The new family migration rules could cause friction too. An income threshold set just above average earnings takes away from most British citizens the right to marry who they choose and settle in Britain. Most ethnic minority Britons won't meet that income test. Gavin Barwell's proposal that the threshold should be lowered, so that a full-time worker on the minimum wage qualifies, might mitigate this.

Ethnic minority voters will not object to a government seeking to manage immigration in the national interest, but “playing the immigration card” as a political tactic to dish Ukip could well reawaken historic issue of mistrust of the Conservatives. Most minority voters value efforts to promote integration. Many may back efforts to manage numbers down in a workable way, particularly if that is combined with balanced language about the positive contribution of immigration too. The evidence from Lord Ashcroft’s in-depth study of minority voters suggests that the key test may be less about policy, but whether the motives behind it are perceived as honest or cynical. 

It would take some heroic assumptions to advocate a so-called immigration ‘amnesty’ as a vote-winning electoral gambit. Nick Clegg’s Liberal Democrats are now ditching the policy, having failed to find an effective way to explain it to voters. 

There is a cogent case for the policy of offering a path to citizenship for undocumented migrants, though it is not a popular one. Zahawi does also makes this pragmatic argument, telling his local newspaper that it is better to have people on the books, paying taxes than working cash-in-hand, with proper checks to ensure employers are playing by the rules and paying the minimum wage. He suggests those allowed to remain might not get full citizenship, though this would create a two-tier system, which did not work well with European guest-worker programmes. It would be better to have requirements and checks that people contribute positively as part of a citizenship deal.

London Mayor Boris Johnson is the most prominent Conservative to argue that there is no practical alternative to offering legal status to those who have been here for some time. People might, one day, be persuaded of this, but it will never happen without securing public confidence in an immigration system that works. The dysfunctional immigration bureaucracy, with its lost files leaving people waiting years for a decision, commands no confidence from anybody as being either fair or effective. So the most compelling public argument against an ‘amnesty’ is that it would just be the first of many, rather than a way of dealing with a historic failure of the system, while putting a robust, effective and fair future system in place.

It would be toxic to this pragmatic case to suggest that giving legal status to undocumented migrants was being done in pursuit of electoral advantage, not to sort out a real problem. Governments might one day need to take the question of undocumented migrants out of the “too difficult to think about box”. Advocates of this policy need to acknowledge its unpopularity – and take the long-term challenge of securing public consent seriously. 

Zahawi is right that the Conservatives definitely need to broaden their appeal to non-white citizens if they want to win in tomorrow’s Britain. Mixing these two issues up risks stalling progress on both.

However, Zahwai’s intervention is a reminder that Conservative voices on different sides of immigration policy debates. Several Conservatives worry that the design of the government’s current immigration cap as too crude. New Downing Street policy chief Jo Johnson MP has said he wants to take international students out of the net migration target. 

Zahawi’s own intervention reflects his pro-market worldview but also a deeply felt sense of gratitude for the opportunities which Britain has offered to immigrants. Zahawi, born in Baghdad, won the Conservative nomination for Stratford-upon-Avon by telling local party members that generations of Zahawis had not farmed in the area since Shakespeare’s time, but that his sense of patriotism and pride reflected the opportunities his family had experienced here, as Iraqi Kurds: 

“Above all, I am committed to freedom and opportunity. Britain gave my father both when he fled here 34 years ago as a refugee from Saddam’s murder squads”, he stated in his election day address. (Zahawi stood for “reducing immigration”, and “deporting illegal immigrants” too).

His new proposal does not work as a pitch for votes. Perhaps Zahawi’s desire to share that British dream with others is a more noble one for that.