The Democrats appear to believe they will win the 2020 Presidential election, no matter who is nominated (similar to how they thought Clinton would win in 2016, but we know how that turned out). As a result, they are competing with each other to move as far left as they can to appeal to the Democrat base who will donate and vote in larger numbers during the Primaries.
Gabbard is probably too moderate to have a realistic chance of getting the nomination. Her lack of playing the hysteria game on topics Democrat party elders want discussed is making it difficult for her to fundraise.
I cannot see Democrats nominating a candidate with a moderate enough platform that has any realistic chance of not getting blown out in the electoral college, let alone win the presidency. Proposals such as the Green New Deal will flip traditional Democrat strongholds such as the "Rust Belt" into Republican strongholds in 2020, and possibly for decades.
Who cares about "traditional democratic strongholds" flipping if the green new deal has 81% support nationwide? GND would change the map by bringing out that silent majority. Lets not forget who won Michigan, Wisconsin, Indiana, Ohio, West Virginia and Pennsylvania and that a moderate democrat lost it.
https://www.huffingtonpost.com/entry/green-new-deal-poll_us_5c169f2ae4b05d7e5d8332a5Also why do you try to frame Tulsi as moderate? She is a progressive who backs free college, medicare for all and off fossil fuels in 15 years. The "democratic base" is moderate.