She's a proven liar. Don't believe proven liars.
It's hard to tell if she is lying or not. Possibly it is true and she has all good intentions for the sake of USA's economy.
It is also possible that she has a selfish intention or she has a large deposit of bitcoins. And possibly you are true in saying that she is a liar and just use this phrases to get more public votes.
All the politicians are liars. Every single time they're making it look like they'd do ANYTHING for their country. This happens just until they've won their wanted positions. After that, everything goes exactly the opposite way, pretending that they didn't even promise all that stuff ever in their lives. You should never trust a politician, IMO.
Politicians promises are two things, either they will really implement it or they will just leave it behind. But they have to win first in the election. We still do not know if its a political strategy, but we can not really eliminate the fact that all their platforms though how committed they are they are all thinking of winning and how to win. So her support for blockchain maybe just a lie or truth but the actual is it all serves her purpose to win the election.