Googling “move to Canada” is easy — uprooting your life to another country is harder. But after former president George W. Bush’s 2004 re-election, U.S. immigration to Canada rose by tens of thousands of people.

Last night, Republican presidential contender Donald Trump moved closer to winning his party’s nomination after Super Tuesday primary victories. Despairing Americans made “how to move to canada” spike as a Google search term, and seem to have overwhelmed a federal immigration site with traffic by the wee hours of this morning.

Americans who emigrate to Canada have any number of reasons – economic, relationship-related, health care-related, political. And one person may have more than one kind of motivation.

However, U.S. immigration to Canada shows a clear relationship to 9/11 and its aftermath. The data (see graph below) shows a clear spike starting in 2003, when U.S. and allied forces invade Iraq, and rising sharply as Bush is re-elected in 2004 and serves his second term. It starts to fall again after President Barack Obama is elected in 2008, but never to its pre-2003 levels.

Some 34,000 more Americans emigrated to Canada in the 10 years starting with Bush’s 2004 re-election than in the previous decade. Immigration from the United States to Canada doubled between 2002 and 2008, from just under 5,000 to just over 10,000.

READ MORE: Move to Canada’ searches spike on Google during Super Tuesday

“I felt very unsafe in New York,” remembers Damian Rogers, who was living in the city during the 9/11 attacks.

“I felt very manipulated by the government. I felt, at the time, very afraid after 9/11, and felt very conscious of that fear being manipulated by the Bush administration. There was an atmosphere of fear that I thought was under a constant state of provocation – it was a very difficult environment.”

“It sounds strange now, to say that I felt safer getting out of the United States, but I did.”

When they’re alarmed or frustrated by their country’s politics, American liberals talk about moving to Canada, an idea Rogers says has its roots in the Vietnam era.

“I was surrounded by a lot of liberals, people I knew in New York, who were always threatening, or joking about moving to Canada when things became untenable politically,” Rogers remembers. “I think that part of it is also a reflection of American arrogance as well – that of course I can just pick up and move to Canada.”

“I don’t think that Americans feel that other foreign countries are as available to them. Part of it is proximity, and part of it is this sense that naturally Canada would be delighted to have me move there.”

“The decision to actually move was pretty impulsive,” Rogers says.  “When I initially moved to Canada, I imagined that I was moving to another city – I was moving to Toronto more than I was moving to Canada.”

“I am quite happy to be here, even though it was not necessarily my intention to become a Canadian, it’s happening to me, and I’m not unhappy about that.”

Google search terms about moving to Canada may be rising now, but they’re dwarfed by the spike they reached after Bush’s second inauguration. (A Google spokesperson says this doesn’t reflect the last few days of searches.)

(American conservatives are not immune. “Move to Canada” +obama spiked in 2008, and was most popular in southern states. Although it doesn’t appear that when push came to shove, many of them actually fled a Democrat in the White House to a land of higher taxes, universal health care, gun control and snow tires.)

“Move to Canada” +trump is still on a spike that began in July of 2015, most popular in northeastern and midwestern states.

U.S. immigration to Canada rose after the September 11, 2001 attacks, the invasion of Iraq and Bush’s second election victory, but that increase is dwarfed by the thousands of Americans, many in danger of being drafted, who fled to Canada during the Vietnam era.

U.S. immigration to Canada, 1955-2014

Click here to view data »