It was successful when trialed in Canada so I'd say its viable. But ya, I don't trust our politicians to be sensible and cut spending to pay for a new program. [e.g. Use this to remove the most inefficient $ for $ welfare related programs so more of it ends up in the hands of the people that need it]
It's important to note that the "Mincome" experiment provided a Guaranteed Minimum income, not a Basic Income. The distinction being that the former started to drop off if the recipients earned more than some threshold (at a rate of $0.50 less per $1 earned, so as not to serve as a disincentive).
This is similar to most basic income or negative income tax proposals. Most finance themselves through progressive income taxes, generally scaled so that those of average income see their taxes increase the same amount as what they receive from BI.