The Defining Issue
I don't think it's generally understood here in Europe how big the immigration issue is in the US at the moment.
As I left the US after a week in New York, Washington and San Fransisco, the Senate had just taken its decision on what President Bush calls a comprehensive immigration reform.
The House has already decided on a more limited policy, focusing on border and enforcement, but offering no path to citizenship for those that have been in the country for a long time.
And now the task is to get the Senate and the House to agree to something that can then be voted on - preferably before the November elections.
Fred Barnes in the Weekly Standard is very clear on the importance of the issue:
"Failure to deliver on immigration reform, the single biggest domestic issue of the decade, would mark the end of the Bush presidency as an effective political force. Bush would become the lamest of lame ducks. His final two years in the White House would be painful."
But the other way around also applies.
If he can deliver on this, he will be seen as having achieved a major break-through on a very major issue, and also done it in a way that is likely to capture the centre ground of the electorate on the issue.
That could be very important.
But it will not be easy. He will have to face down some very hard-nosed and semi-xenophobic voices. And there will be elements on the Republican party that will have difficulties.
So far he seems committed to stay the course on the issue.
Whether it is the "defining issue of the decade" or not - the defining issue at the moment it certainly is.