I ain’t popping champagne corks yet - this particular poll has been an outlier for some time, although in the past an outlier for Cruz.
The other factor is cross over votes from Hillery voters. Cruz got a ton of those in WI, so much so that she lost a state she was up by close to 10. The rats do not want to face Trump.
Still best to be cautious. Believing this poll entirely could produce a hard fall come Tuesday night although I hope its true.