The election marked a major shift in Danish politics: It was the first time that the right leaning parties held an outright majority in the parliament since the beginning of the modern democratic system in Denmark in 1901. (Although right leaning parties had held power numerous times, they had always had to share power with more centrist or leftist parties in coalition governments.) Historian Bo Lidegaard believes that the vote showed a move away from broad national consensus which had existed since the 1930s about the style of governance in Denmark. One of the most important changes that forced the change was the rise of immigration as a political issue and the ensuing rise of the Danish People's Party. Immigration played a central role in the 2001 campaign. It was thrust into focus by the 11 September 2001 terrorist attacks in the United States, but had been gaining attention for years.