Is Portland worth a visit from Seattle?

Unless you carry a Canadian passport you won't be allowed into Canada right now. But I'm not sure Portland's any better than Seattle in terms of street violence. TBH I'd probably be looking at the San Juans and some of the other unscathed places to the north of you that are still in the US. 

Yes, Portland is worth at least a year's visit (not just a day).  We have a lot more nature than Seattle.  There are at least 279 city parks in Portland alone, and each of the suburbs have at least a few.  Portland is ranked #2 in the world for bicycling.  There are at least 25 miles of riverfront along the Columbia River, and about twice that along the Willamette River.

The U.S.'s monster of urban parks is Forest Park which has over 70 miles of hiking trails in 5,000+ acres and—like its name suggests—is tall evergreen forest.

Or, if you have in mind a more cultivated outdoor park, there is 410 acre Washington Park in the west hills adjacent to downtown Portland which contains an arboretum, rose garden, Japanese garden, tennis courts, forestry museum, children's museum, numerous memorials, hiking trails, and more.

Portland is worth visiting, but Seattle is actually superior. Portland and Vancouver WA are 2 very white cities, but Portland is much bigger and more liberal.

sure, However this year is all jacked up due to this coronavirus bullshit which is just to get Trump out office. 

you should come when its Rose Festival time, which has been cancelled this year due to the coronavirus bullshit.

BTW, the greyhound station right next to the Amtrak station is closed and it has turned into a LARGE homeless camp.

God Bless

If you're choices are Portland or Vancouver BC, definitely Vancouver!!!  You will need a passport to cross the boarder though.  Vancouver is one of the most beautiful cities in the world, my opinion.  I'd recommend spending your time in Vancouver over Seattle actually.  The interesting two/three day trip from Vancouver is Victoria BC.

If you really enjoy nature, I'd strongly recommend going over to Olympic National Park, in particular the Hoh National Rainforest.  https://www.nps.gov/olym/planyourvisit/visiting-th... 

Another nature trip worth considering out of Seattle is to Mount Rainer.  

If you went to Oregon, I'd suggesting skipping Portland and going straight out to the sea coast, drive Hwy 101 down the Oregon coast.

You may or may not be allowed International travel this July. Go where you go.

Can you have a grand time in Portland? Yes and it is just a few minutes from Vancouver Washington. Some reason you cannot vist both Vancouvers?