If you’re going to pay attention to Congress, do it now. Lawmakers are on the verge of returning to Washington after a lengthy recess. But the 2020 presidential sweepstakes will soon eclipse everything on Capitol Hill.

President Trump’s 2016 victory represents one of top upsets in American political history. Everyone is bracing for a competitive 2020 campaign after the Electoral College awarded the presidency to Mr. Trump four years ago. Democrats are still months away from sorting out their standard-bearer to challenge the president.

Yes, control of the House and Senate will be in play. At this stage, the Senate is looking like a stronger bet. But the presidential race will dwarf anything in Congress ... with a few exceptions.

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For example, if House Democrats truly try to impeach Trump. Or, if there’s another government shutdown, the U.S. attacks Iran or North Korea, Congress actually approves serious gun legislation, or the Dems' presidential nominee comes from Capitol Hill. The field has remained extensive: Sens. Elizabeth Warren, D-Mass., Kamala Harris, D-Calif., Cory Booker, D-N.J., Michael Bennet, D-Colo., Bernie Sanders, I-Vt., Amy Klobuchar, D-Minn., Reps. Tulsi Gabbard, D-Hawaii, and Tim Ryan, D-Ohio.

For the record, if Gabbard or Ryan somehow rallies to erase a seven-run deficit in the bottom of the ninth, Nationals-over-Mets style, then we've got a real story.

Impeachment and investigation of Trump and his administration likely will consume a lot of news oxygen in Washington when Congress returns to work next week. Expect to hear a lot about how many Democrats favor impeachment or an inquiry, and where the Judiciary Committee stands with subpoenas for people like former White House Counsel Don McGahn.

There will be lots of chatter about guns, too.

But the House Judiciary Committee must first hold a “markup” session on those bills. The panel is expected to hold a hearing on banning military-style weapons late this month, but the House lacks the votes to pass such a prohibition. And Senate Majority Leader Mitch McConnell, R-Ky., has reiterated that he's not interested in entertaining legislation unless it’s destined to secure Trump’s signature.

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The House’s legislative traffic for next week doesn’t grab the biggest headlines. The House is tentatively scheduled to debate a bill about the Florida coastline, a measure to protect the “Arctic Cultural and Coastal Plain” and legislation dealing with “marine economies.” These plans would bar drilling and impose other environmental protections. A memo to Democrats from House Majority Leader Steny Hoyer, D-Md., mentioned guns, but offered no timetable for legislation in the House. Democrats are expected to hold a forum Tuesday to try pressuring McConnell to consider gun measures.

Granted, Democrats clearly have wanted a bona fide outcome when it comes to firearms legislation. But, they also could try using what they've seen as McConnell’s recalcitrance on guns as a political opportunity heading into 2020. McConnell is up for reelection. That seat may be hard for Democrats to win. But, the party could deploy guns as a wedge in states with competitive Senate elections in 2020. Such a tactic could help Democrats try to flip seats into their column.

Democrats will attempt to capitalize on this among suburban voters in states which could be in play. Consider Senate Democrats’ efforts to topple Sens. Martha McSally, R-Ariz., Cory Gardner, R-Colo., Joni Ernst, R-Iowa., John Cornyn, R-Texas, and David Perdue, R-Ga. Remember that Republicans likely will have to defend two GOP Senate seats in Georgia next year once Republican Gov. Brian Kemp appoints a successor to Republican Sen. Johnny Isakson. Isakson said he’s resigning at the end of the year due to health concerns.

Lawmakers also need to fund the government by October 1.

The Senate Appropriations Committee has been planning to prep four of the annual 12 spending bills in the middle of the month. Those measures would fund the State Department, energy & water programs, the Departments of Labor & Health and Human Services and the Pentagon.

The House has okayed ten of the annual 12 bills, but those bills would be dead on arrival in the Senate. The House would have to compromise with the Senate to come to an agreement on everything. Hoyer’s letter indicated lawmakers would craft a temporary measure to fund the government to avoid a shutdown in less than a month.

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Defense hawks secured a reasonable gain in Pentagon funding in the recent budget accord, but a stopgap plan for the military would constitute something of a setback. Many pro-defense lawmakers backed the budget blueprint earlier this summer because it helped give the Pentagon certainty.

Rep. Mac Thornberry, R-Texas, the top Republican on the House Armed Services Committee, says he backed the budget package only “because of the incredible benefits that come from stable and predictable funding.”

President Trump’s decision to redirect funding for his border wall from “military construction” projects could prompt Democrats - and frankly, some Republicans - to attempt to harness future repurposing efforts. There have been serious questions as to whether the fiscal reprogramming maneuver is Constitutional. After all, Congress retained the power of the purse, not the executive.

The decision to divert funds drew the ire of Thornberry.

“Rebuilding military infrastructure is a critical part of that recovery and a bipartisan priority. It is important that Congress now restore the military construction funding diverted for border security. Failing to do so only forces our troops to pay for political discord in Washington,” Thornberry said.

But, the biggest decision would how House Democrats approach impeachment. The party’s internal wrestling match over impeachment would open a door for Republicans to lambaste their opponents. Democrats have been dithering on impeachment – and simultaneously ramping things up.

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This would give Republicans an opportunity to portray all Democrats as taking an “extreme” position with impeachment. That could work against Democrats – and, frankly, filter into the 2020 race. As this drags on, the party’s presidential contenders will have to stake out positions on impeachment. Those candidates may not like President Trump, but impeachment is another question.

This is where the Congressional universe would collide headlong into the presidential race in 2020. And, few will pay attention to much else coming out of Congress until the final votes are cast next fall.