WASHINGTON — President Obama is treating his drive to win congressional support for his nuclear deal with Iran like a political campaign, making attacks on opponents that need to stop, Senate Majority Leader Mitch McConnell said Thursday.

McConnell’s comments came as the Senate left town for a summer recess that both sides in the dispute plan to use to try to line up support for showdown votes next month. They followed a tumultuous early debate over the nuclear agreement in which Republican opponents have strongly criticized Obama.

Obama “is treating this like a political campaign,” McConnell said. “Demonize your opponents, gin up the base, get Democrats all angry and, you know, rally around the president. To me, it’s a different kind of issue.”

The majority leader has said he wants senators to spend next month’s debate over the Iran deal planted in their seats – an unusual step underscoring the issue’s gravity.

McConnell, R-Ky., also said:

 Congress will pass no major immigration overhaul through next year, which he blamed on anger over Obama’s efforts to unilaterally ease restrictions;

He will not allow fights this fall over spending and cutting federal money for Planned Parenthood that could lead to a government shutdown;

Pope Francis’ first-ever papal address to Congress on Sept. 24 has sparked the most requests for invitations he’s aware of for any speech to Congress.

Lawmakers are required to vote on whether to accept the Iran agreement by Sept. 17. Opposition is almost solid from Republicans arguing that the U.S. gave away too much in negotiations and from many Democrats sympathetic to Israel, which considers the pact a disaster.

It’s nearly certain that the GOP-controlled Congress will reject the deal, and that Obama will veto that bill. The suspense is over whether Obama can corral enough Democratic support to sustain his veto and keep the agreement alive.

“It’s those hard-liners chanting ‘Death to America’ who have been most opposed to the deal,” Obama said of Tehran demonstrators in a speech Wednesday. “They’re making common cause with the Republican caucus.”