We don't need to send "boots on the ground"; just help Ukrainian defenders with weapons.
It's not even clear that the issue is weapons. This isn't 1980s Afghanistan we're talking about. Ukraine is a former member of the USSR and was within spitting distance of NATO, so they're armed with fighter and attack aircraft, helicopter gunships, transport aircraft, artillery, armored personnel carriers, etc. etc. The Ukrainian military clearly has issues that have nothing to do with armaments- early on in the conflict, a group of soldiers simply surrendered their armored personnel carriers without a shot being fired, so there are major issues with leadership, discipline, morale, and organization. This is where U.S. military advisors could play a key role, and the U.S. has sent advisors over there, and presumably they're offering intelligence support such as satellite photos as well. The fact that the Ukrainian army is getting its shit together may be related to this. The fact that Russia has kept escalating the situation is in fact evidence that it's working; if the rebels were doing well against the government, they wouldn't need to intervene.
But the charlatan-in-chief would not even send Ukrainians the perfectly defensive helmets and body armor
This is just misleading. The US has sent body armor and night vision goggles. Perhaps more importantly, the West has committed $27 billion in aid to Ukraine over the next two years. With that kind of financial backing, they can simply buy whatever equipment they need.