Gov. Cuomo’s political operatives are eyeing a “painful scenario’’ to dump Kathy Hochul, a moderate upstater, as the governor’s running mate for lieutenant governor amid growing signs that leftist law professor Tim Wu is picking up momentum in the Sept. 9 Democratic primary.

Such an action could be needed because a Wu victory would result in a Cuomo/Wu ticket on the Democratic line in the November election but potentially disastrous Cuomo/Hochul tickets on the Working Families, Independence, and Women’s Equality lines, where no primaries are slated.

Under the state Election Law, votes for a Cuomo/Hochul ticket in November would not be added to the tally for the Cuomo/Wu ticket, potentially costing Cuomo hundreds of thousands of votes.

Cuomo would have until Sept. 16 under the election law to swap Wu for Hochul, using a technique that would allow the former Buffalo-area congresswoman and lawyer to be nominated instead for a judgeship, according to an expert on legislative election law.

“This is the painful scenario being reviewed by the Cuomo people, who realize that there is an outside possibility that Wu could win the primary,’’ said a source close to the Cuomo campaign.

Wu won the surprise endorsement of The New York Times as well as other left-of-center groups last week as they criticized Hochul’s past opposition to state aid for illegal aliens and her 100 percent rating from the National Rifle Association.

Wags in the political world, referring to a “Wu is me’’ electoral outcome for Cuomo, are joking about the office a re-elected governor would assign to Wu if he does become lieutenant governor.

Among the possibilities: (1) the dank and dusty P-1 subterranean parking garage adjacent to the state Capitol; (2) the lonely one-man State Police security booth that leads to the Capitol’s historic carriage entrance; and (3) the tiny unmarked men’s room opposite the governor’s secretary’s office on the third floor of the Capitol.

Meanwhile, Cuomo campaign operatives, nervous about the Sept. 9 primary, privately concede that he would suffer considerable national political damage if Fordham University Professor Zephyr Teachout, the governor’s hard-charging “progressive’’ challenger and Wu’s running mate, gets more than about 30 percent of the vote.

“About 30 percent will be a huge embarrassment to Cuomo on the national scene and would reinforce the sense that progressives don’t like or trust him,’’ said a prominent Democratic activist.

Several activists told The Post they believed that Teachout, who has been endorsed by the state’s second-largest public employee union, would hit 30 percent.

Comedian/activist Randy Credico, who is also running a spirited campaign in the primary, could pull a vote in the high single digits, further weakening Cuomo’s tally, the activists agree.

GOP gubernatorial hopeful Rob Astorino, short on money and trailing Cuomo badly in the polls, will make a bold move for African-American support Wednesday at the National Baptist Convention in New Orleans.

Astorino, a social conservative who opposed New York’s legalization of same-sex marriages, plans to tell more than 1,000 New York ministers that he, not Cuomo, represents the traditional social values that their congregations support.

The event is one leg of Astorino’s “under the radar screen’’ effort to line up voter support from traditionally Democratic voting blocks.

“This is part of our outreach effort, something we’ve been doing throughout the campaign,’’ said Astorino spokeswoman Jessica Proud.

Astorino, the Westchester County executive, has been supported by several prominent African-American leaders and won the votes of large numbers of black voters in his past campaigns.