Tha figure rose to seven in Thursday's voting.
Yet, if we remain fixated on the constitution and neglect to debate properly the record of the Scottish (and UK) government, why would people vote for anyone except the SNP and, to a lesser extent, the Scottish Conservatives?
"The SNP vote is crumbling in their heartlands.it's a very bad night for the SNP", she said. Whether or not this diminishes their support for Scottish independence remains to be seen.
The Conservatives found that this approach helped them regain ground in Scotland: they became obsessive in their declaration that the SNP is obsessed by the prospect of another referendum.
The party ended the night with 35 MPs and just under 37% of the vote - a result substantially down on the 50% of the vote they secured in 2015 which gave them 56 MPs. For the past decade, the SNP has been able to claim victory in just about every electoral contest it has fought.
The Prime Minister saw her slender Commons majority wiped out and the Conservatives returned to power as a minority Government, propped up by Northern Ireland's DUP.
"In a land where the word "Tory" is still often used as a curse, she has detoxified the brand and produced a thumping success even as Theresa May fouled up across the rest of the United Kingdom", says Chris Deerin in The New Statesman.
He was elected Deputy Leader of the party just a year ago. Even the Liberal Democrats won back some credibility with four seats (an increase of three). Once the dominant party in Scotland, Labour had been expected to struggle as pro-independence Labour supporters left for the SNP and pro-union voters moved to the Tories.
So what caused this remarkable shift in the Scottish political landscape? Like many people, I thought most analysis of the Scottish political landscape post-general election could be expressed before we fully knew the results, so I wrote the bulk of this piece early on, before reflecting on the way things actually played out.
Mr Rennie said a vote should be held in Holyrood to "sist, delay and stop" another referendum in the current parliamentary term.
Among the biggest surprises on the night was the success of Scottish Labour.
In reality, such a large proportion of SNP MPs was never really representative of the country, and the only direction the SNP could go in this election was downwards.
Brexit has not altered the dynamics of Scottish independence anywhere near as much as seemed likely nearly a year ago, when a majority of Scots voted to remain in the European Union.
It is likely that Jeremy Corbyn's unashamedly social democratic manifesto was a major draw for these voters, and some of them may have voted for Labour at the expense of the SNP.