Republican donors are hedging their bets

Republicans, backed by moneyed interests such as real estate, have for years consistently out-raised the Democrats. They still lead the Democrats in campaign funds this year — but the gap could have been larger, had it not been for some outside groups that seem to be sitting this year out.

New Yorkers for a Balanced Albany, a well-funded PAC that supports charter schools, donated close to $7 million to Republicans in 2016, with nearly $6.6 million already infused by the end of October. But this year, as of the same time, the group had spent only $1.2 million.

Some traditional Republican donors have also started giving to Democrats, perhaps to make sure they are in the good graces of the party that comes out on top.

For example, the Real Estate Board PAC, which gave more than $260,000 to the Senate Republican Campaign Committee in 2016, had given them only $120,000 this year, as of the most recent filing. And it has donated $95,000 to the Democrats’ committee, after giving nothing in 2016.

Scott Reif, a spokesman for the Senate Republicans, dismissed the lower spending totals, pointing to other groups that have ramped up their spending, such as Balance New York, a PAC funded by real estate, that had spent $1.8 million as of Nov. 1.

Voters are feeling the blitz

The flood of campaign cash has meant that voters in competitive districts are seeing a torrent of television and digital advertisements, mailers and paid canvassers.

Mr. Gaughran said he had opened four campaign offices across the district, hired twice as many staff members and was flush enough to be able to reimburse the expenses of a squadron of volunteers 20 to 25 times larger than in his last unsuccessful run in 2016.