It's very important for Trump that he carry Pennsylvania again in 2020. This could be quite difficult for him, judging from recent trends in the Keystone state. An article by Paul Kane in the Post collects a lot of the reasons why and in the process makes it pretty clear what the Democrats need to do in 2020 to win the state.
"President Trump’s biggest 2016 upset took a very sharp turn this year away from Republicans.
Look at Sen. Robert P. Casey Jr.’s more than 13-percentage-point victory last month, only to be topped by Gov. Tom Wolf’s 17-point reelection win. Those Democrats torched the four suburban counties surrounding Philadelphia and Allegheny County, home to Pittsburgh and its inner suburbs, by margins never before seen.
Take Chester County, the wealthiest in Pennsylvania, due west of Philadelphia. Hillary Clinton broke through the traditional GOP stronghold in 2016, winning by 9 percentage points over Trump. Casey won there by 20 percentage points.
“You can’t attribute that just to a verdict on me,” Casey said in an interview inside his Senate office, giving Trump’s unpopularity much of the credit.
Wolf won there by 24 percentage points, actually topping Clinton’s raw vote total in Chester County from the higher-turnout 2016 race....
The broader problem was spelled out by G. Terry Madonna, who runs the Center for Politics and Public Affairs at Franklin & Marshall College, and Michael L. Young in a memo laying bare the Republican struggles:
* Democrats have won four of the past five governor’s races, each by more than 9 percentage points;
* Republicans lost 11 seats in the state House and five in the state Senate, creating the chance for Democratic majorities after 2020;
* Republicans performed even worse in down-ballot statewide contests: They have lost six straight races for state auditor, four straight for state treasurer and two straight for attorney general....
Of eight statewide races in the past three elections, Republicans won just two — Trump and Sen. Patrick J. Toomey (R), both in 2016.
Two Pennsylvania Democrats, state Attorney General Joshua Shapiro and Treasurer Joseph Torsella, actually received more votes than Trump two years ago.....
Casey believes a Democratic presidential nominee, man or woman, can keep Trump’s margin down in the rural towns if they follow the Wolf-Casey approach.
“Get there physically, listen to them, show up and give a damn,” he said.
His first ad, run heavily in the western part of the state, showed coal miners talking about Casey’s legislation to help with their health benefits. A second ad showed a mother talking about the opioid epidemic in that part of the state.
Clinton devoted outsized attention to Pennsylvania, including an epic election eve rally outside Philadelphia’s Independence Hall with Bruce Springsteen, Katy Perry and the Obamas.
But her campaign focused heavily on liberal cultural issues, running ads that questioned Trump’s fitness for office. She received just 26 percent of the vote in the rural areas and small towns, according to exit polls.
Last month, Casey received 44 percent of that same region’s vote.
That came despite an ideological transformation in which he abandoned the culturally conservative views of his late father, former governor Robert Casey Sr.: The son now supports most gun-control proposals and in 2013 backed same-sex marriage.
His message for 2020 contenders is to follow that same path. The nominee will not abandon Pennsylvania’s urban or suburban voters, the new Democratic base. He or she does not need to win a majority in small rural towns, but must do better than Clinton."
That shouldn't be too tough.