According to the campaign they have now surpassed 1.1 million signatures. Under Florida law a constitutional amendment needs just under 700,000 valid signatures to make the ballot. Since a certain number of signatures are almost always thrown out the campaign has built themselves what should be a sufficient buffer.
If the measure is certified to appear before the voters it will need to get 60 percent of the vote to be approved. Fortunately, most public polling shows its support well above this threshold.