Story highlights

Congress comes back Tuesday from a five-week summer recess

Congress's agenda includes the Iran nuclear deal, funding the government and the visit of Pope Francis

Washington CNN  — 

Get ready for the September scramble.

After more than a month off, lawmakers return to Washington on Tuesday facing the most frenetic agenda in recent memory.

By the middle of September, Congress will have to decide whether to block President Barack Obama’s historic nuclear deal with Iran. Lawmakers are also staring down a September 30 deadline to avert the second government shutdown in two years – a debate that’s increasingly divisive as it becomes tied to the Planned Parenthood controversy.

And in between these two showdowns, Pope Francis will become the first pontiff to address a joint meeting of Congress – a speech that will almost certainly highlight issues that make both parties uncomfortable.

In a Congress that has lurched from crisis to crisis in recent years, lawmakers have struggled to address even the most basic issues without drama. With so many historic decisions to make at once, this is sure to be a September to remember.

Here’s what to expect:

Iran nuclear deal

House and Senate votes on the Iran nuclear agreement are expected this week, but they are more about messaging since the White House has already secured enough votes to preserve the deal. Last week, Maryland Democratic Sen. Barbara Mikulski became the 34th Democrat to come out in favor of the agreement, giving the President the votes to uphold a veto on a Republican resolution to block it.

Supporters continue to try to get enough support from undecided senators to prevent Republican leaders from even holding a vote on the controversial deal. They need 41 votes to block debate and currently are just shy of that threshold.

While the fight on the Iran deal is over in practical terms, the political war over the issue will continue through the next election, when Republicans vow they will elect a president who will roll back the agreement. Both Senate Majority Leader Mitch McConnell and House Speaker John Boehner argue that a majority of both chambers oppose the deal and point to some polls that show most Americans are critical.

“If people vote for me, they know they’re voting to get rid of that deal on the first day of my presidency,” promised Florida Republican Sen. Marco Rubio, a presidential candidate.

The rhetoric will escalate Wednesday when a tea party group has scheduled a rally outside the Capitol to oppose the Iran deal. Headlining the gathering will be two Republican presidential candidates: Donald Trump and U.S. Sen. Ted Cruz of Texas.

The deadline for Congress weighing in on the nuclear agreement is September 17. If both chambers are able to pass the resolution to block it, the House would vote first on overriding the President’s veto. House Minority Leader Nancy Pelosi proclaimed last week that she is “confident we will sustain the President’s veto in both houses of Congress.”

Pope Francis’s historic visit

The hottest ticket in Washington will be to the September 24 speech by the extraordinarily popular Pope Francis in the House chamber. Boehner, who is Catholic, has tried to secure a papal appearance since he was first elected to Congress in 1990.

Only a select few will get a seat inside. Boehner imposed a rule barring former members from using their floor privileges to attend, and each congressional office is given just one ticket for a seat in the visitor’s gallery. Due to intense interest, a series of Jumbotrons will be set up on the West Front of the Capitol so the public can watch. The Pope is expected to appear briefly on a Capitol balcony to see the crowd. A limited number of tickets close to the balcony will go to House and Senate offices, some of which are setting up lotteries online to decide which constituents will get the coveted passes.

McConnell told reporters last month: “We have more requests for this appearance than anything anybody can ever recall around here.”

Even as members from both parties say they are excited about the Pope’s speech, there could be awkward moments. Most Republicans don’t agree with Pope Francis’ statements criticizing capitalism and promoting permissive immigration policies. Many Democrats are at odds with the social policy positions of the Catholic Church, although the Pope has made some modifications recently.

Possible government shutdown

Here we go again. Congress faces a September 30 deadline to pass legislation to fund the government, but a fight over abortion politics is threatening another possible shutdown.

Republican leaders are expected to unveil a short-term funding bill that keeps federal agencies running through the fall or mid-December, but conservatives want to strip out federal funding for Planned Parenthood. That’s a non-starter for most Democrats, and the White House says the President would veto such a bill.

Multiple congressional committees launched investigations this summer into Planned Parenthood after an anti-abortion group released a series of videos that it says prove that some affiliates are selling fetal parts for profit. The group denies the allegations and has released its own report saying the videos are heavily edited.

McConnell, who has repeatedly insisted there will be no shutdown, acknowledges Republicans don’t have the votes to force the President’s hand on the issue.

“I would remind all of your viewers: The way you make a law in this country, the Congress has to pass it and the President has to sign it,” McConnell told WYMT, a Kentucky TV station, last week. He added, “The President has made it very clear he’s not going to sign any bill that includes defunding of Planned Parenthood, so that’s another issue that awaits a new president hopefully with a different point of view about Planned Parenthood.”

An effort to pass a bill defunding the group failed last month in the Senate. But Cruz – who in the past has led high-profile efforts to block legislation he opposes – has vowed to use every procedural tool at his disposal to ban federal funds for Planned Parenthood.

House and Senate Republican leaders are urging their members to focus on the investigations, not another spending fight they don’t think they can win. They believe the public hearings can potentially increase public pressure on Democrats and the White House.

One idea leaders are considering is to include a provision to defund Planned Parenthood into a separate legislative package that repeals key parts of Obamacare. The so-called “reconciliation” bill allows the Senate to pass legislation related to the deficit with a simple majority, not the 60 votes most legislation needs to pass the Senate.

While approval of a short-term “continuing resolution” averts a shutdown, it’s a temporary Band-Aid. Partisan fights over the annual spending bills have caused the process to stall out, and leaders from both sides say the only way to find any medium- or long-term solution is to broker some type of broad bipartisan budget deal between the White House and Capitol Hill.

“Our Democratic friends want to spend more on everything. We’d like to spend more on defense. And so there will be a sort of grand negotiation here in the fall between the two sides over just how big the discretionary budget of the United States government ought to be and how it ought to be spent,” McConnell told WYMT.

Congress will also need to address the debt ceiling, and that could be potentially wrapped into some kind of year-end budget deal. The debate over the nation’s borrowing authority is always contentious because conservatives don’t want to increase the debt limit without imposing new spending cuts.

More fall fights on the horizon

Those Senate Republicans running for president are expected to try to use their positions to make a mark in the crowded 2016 GOP field in the hopes they can raise their poll numbers after weeks of Trump dominance.

That’s likely to cause McConnell headaches given the list of high priority bills he needs to get done this fall.

Boehner also has to deal with familiar fights with members of the right in his conference. Earlier this summer, one conservative, North Carolina Republican Rep. Mark Meadows, attempted to oust Boehner by offering a resolution to remove him as speaker. The challenge went nowhere, and Meadows told CNN that for now he’ll hold off pushing for a floor vote until he evaluates how much input from him and other conservatives is included in leadership decisions in September.

“The only fair thing to do is see if that process is fixed,” Meadows told CNN by phone last week.

Funding for federal roads, bridges and transit projects will expire at the end of October so Congress will need to come up with a proposal to add money to the highway trust fund. After 35 short-term extensions, leaders of both chambers are hoping to find agreement on a five- or six-year deal.