The Note: Fundamentals of 2020 race show signs of shifting

The TAKE with Rick Klein

President Donald Trump returns to the campaign trail on Monday in an awkward posture: playing defense.

A Republican member of Congress -- the first -- has come out for Trump's impeachment. Red-state abortion bans have Democrats energized and Republicans, including the president, are not really wanting to defend the new laws.

Trump's biggest legislative gambit of the year, an immigration proposal, doesn't have united GOP support, much less any Democratic backers. World events and a trade war are challenging the president's foreign-policy stances and threatening to disrupt the economy.

And right where the president will campaign Monday night, in Pennsylvania, the specter of the leading Democratic candidate looms.

"President Trump inherited an economy from Obama-Biden administration, that was given to him, just like he inherited everything else in his life," former Vice President Joe Biden said at his first major campaign rally in Philadelphia over the weekend.

Yes, Democrats are divided as they hash through their field of 23 candidates. But the other side is no portrait of unity, as fundamentals about the 2020 race could be shifting.

The RUNDOWN with MaryAlice Parks

Subcommittees of the Senate Armed Services committee are slated to begin hearings this week on the National Defense Authorization Act to fund the military. The Democratic-controlled House will begin hearings the first week of June.

Because of their size and scope, these bills are notoriously hard to finish, even though there's significant bipartisan collaboration on the issues.

This year, politics and crises at home and abroad will likely make this work even more challenging than usual.

Earlier this year, both parties worked together and passed a resolution urging the U.S. to withdraw support of Saudi Arabia's military action in Yemen. Likewise, a majority in Congress voted against the president's use of a national emergency to divert Defense Department funds to build a wall at the U.S.-Mexico border. Trump vetoed both.

Capitol Hill holds the power of the purse and so, in a system of checks and balances, members of Congress, in theory, could use this moment to put further pressure on the commander-in-chief to listen to Capitol Hill.

The TIP with Zohreen Shah

Sen. Kamala Harris, D-Calif., unveiled a proposal Monday morning to close the gender pay gap -- and hold corporations accountable if they don't comply.

The plan would make large companies pay a fine if they don't obtain an "equal pay certification" from the Equal Employment Opportunity Commission. A senior campaign official says for every 1% wage gap that exists, the company would be fined 1% of its profits. They will additionally be required to post on their company's website if they are certified with paying men and women equally.

Harris plans on using money from the fines to fund family and medical leave. The senior campaign official says that a similar law was recently put into effect in Iceland and that in America, women who work full time are paid roughly 80% of what their male counterparts make, and women of color make far less. Harris has made a big push for equality within her own campaign; a spokesperson recently told ABC News that 11 out of 19 senior staffers are women.

THE PLAYLIST

ABC News' "Start Here" podcast. Monday morning's episode features ABC News Deputy Political Director MaryAlice Parks, who breaks down the 2020 ramifications of the restrictive abortion bills in Alabama and Missouri. And ABC News' Anne Flaherty breaks down the proposed plan from Customs and Border Protection to transport migrants from the Southern border to Florida: "This crisis at the border is starting to spill into the interior of the U.S." http://apple.co/2HPocUL

WHAT YOU NEED TO KNOW TODAY

Download the ABC News app and select "The Note" as an item of interest to receive it every weekday.