That splashing sound is the rats jumping overboard:
Corporate America is already thinking beyond Election Day, increasing its share of last-minute donations to Democratic candidates and quietly devising strategies for how to work with Democrats if they win control of Congress.
The shift in political giving, for the first 18 days of October, has not been this pronounced in the final stages of a campaign since 1994, when Republicans swept control of the House for the first time in four decades.
. . .
An analysis by The New York Times of contributions from Oct. 1 to 18, the latest data available, shows that donations to Republicans from corporate political action committees dropped by 11 percentage points in favor of Democratic candidates, compared with corporate giving from January through September.
Republicans still received 57 percent of contributions, compared with 43 percent for Democrats, but it was the first double-digit October switch since 1994.