Who is a more opportunistic grifter, anyone in the Lincoln Project (take your pick) or Donald Trump?
Lincoln project. No question.
This is a bit of a surprise because you're generalizing rather than naming someone. The Lincoln Project has more than a half-dozen co-founders. The only founders I know by name are Conway, Schmidt, and Wilson (I also know of at least one pedophile by reputation). Conway and Schmidt have since left the group.
According to conservatives plugged into these social circles, as far as I have been able to discern, Conway is probably a real movement conservative. Some have said Schmidt is probably an opportunist. I haven't heard much on the personal side for Wilson, but I'd assume he's like Schmidt except a little more opportunistic and a lot more vulgar.
That isn't an endorsement of Trump either, nor is it even a claim of principle on his part. But it's not a grift. He was making plenty of money before his presidency. He didn't need to become President to be rich, and becoming President didn't make him significantly richer, if at all. In terms of the effort required for the payoff, it doesn't make sense. There are all sorts of other cynical reasons you could attribute to Trump for why he ran for office (megalomania, for example), but grift really isn't near the top of the list.
I do believe that Trump is primarily motivated by a need for attention, and a key part of that is being perceived as rich, powerful, and beyond great. But his incessant need for attention goes hand-in-hand with grifting: Trump Vitamins, Trump University, Trump Water, Trump Vodka, Trump Steaks, Trump Airlines. Donald Trump and the Trump brand are almost inseparable.
Someone can still be a grifter/huckster without being motivated by the promise of riches.
But the Lincoln Project folks basically don't have any other marketable skill. This is what they have learned to do for a living.
I'm sure most of these Lincoln Project guys have made plenty of money working within Republican politics. What would jeopardize them from continuing to rake in the cash? Typically, the argument is that they made a calculated jump to grab MORE money. It's also important for aggrieved conservatives to charge apostates with seeking "respectability" and -- always -- admittance to fancy cocktail parties. And that could certainly be part of it, in which case the grifting is not purely about money.
These guys were Republicans back when Trump was a Democrat. These guys were Republicans when Trump was in the Reform Party. These guys were Republicans when Trump was an Independent.
Money is a reasonably good proxy for self-interest, but humans care about other things. I think Trump is a person who obviously -- obviously -- cares more about himself than any political cause (and it's not even close). The trick has been to make Trumpism into a political cause.