Politicians' Conundrum

Yes, whatever the hell this means

Paul Krugman in NYT writes that Politicians(TM) pursue certain policies -- say, a massive tax cut for big corporations and the 1%, in an environment of record-high corporate profitability and government budget deficit -- despite wildly negative public opinions, because of three fallacies:

1. Pundit's fallacy: that a politician will improve her standing if she achieves what pundits say she needs to do.  Republicans used to know that they win elections in spite, not because, of their economic program, but they've been living in a bubble for so long, that they imagine the gospel of supply-side economics would become reality if it's preached loud enough.
2. Points on the board fallacy: that a politician could improve her standing if enough "wins" rack up.  This is the Donald Trump motto: "we're going to win so much, we will be tired of winning."  Worth pointing out: Obama and the democrats passed many legislative victories during his term, but was demolished and lost both houses in the midterms.
3. Post-career endgame.  A congressperson may buck the party line to win voters, but nobody really knows their representatives anyway;  she would rather position herself for a lobbying/think-tank/Fox News pundit job when she loses re-election -- in which case the best bet is to keep donors and the party happy.

For Republicans, the main argument for pursuing their economic policies now, when they're wholly unpopular and the timing is horrible to do so, is largely driven by their dire political situation.   They have control of all three branches of government, and they know they may lose control of the legislative branch in the 2018 midterms.  Henceforth, their razor-sharp focus on cutting taxes NOW.  Because if not now, when?