Sirhan Sirhan granted parole..

Only 13 states (and Washington, DC) held primaries in 1968.  Kennedy wanted either the incumbent, LBJ (his older brother's Vice-President), or Eugene McCarthy to drop out of the race, because he thought that he could win against one of them but not against both of them.  Neither did until after the New Hampshire Primary.  After a worse-possible scenario of LBJ beating McCarthy narrowly in New Hampshire, RFK entered anyway.  LBJ dropped out a little more than two weeks later.

RFK got in too late to be anything more than a write-in candidate in the next three primaries, and McCarthy won all three, including (ridiculously) Massachusetts 49-28. 

Of the 9 remaining primaries, 8 were open with Ohio being uncontested.  (All of Ohio's votes went to favorite son, Stephen Young.)  Kennedy did not campaign in Florida, believing (correctly) that favorite son, George Smathers would win.  

So, Kennedy basically used his final 82 days to concentrate on seven states (and DC): California, Illinois, Indiana, Nebraska, New Jersey, Oregon and South Dakota.

Oregon was third among the states by itself with two empty weeks leading up to it.

As such RFK crisscrossed Oregon.  He visited the Northwest Coast, the Valley, Southwest Oregon and Eastern Oregon. 

His last push was the day before the Primary, May 27, 1968.  RFK went to Springfield, Eugene, Roseburg, Grants Pass, Medford, Corvallis (Benton County Courthouse Lawn), Milwaukee and Portland.  After campaigning for 14 hours, he then departed Portland to head to the Ambassador Hotel in Los Angeles to start his push to win California with the hope of becoming the presumptive frontrunner.  

McCarthy won Oregon 44-38.  After campaigning all over Oregon, RFK said that the problem was that Oregon was one big suburb without any real problems.  RFK saw himself as a problem-solver and that his message did not resonate outside of his usual victory with young voters.

Sirhan Sirhan shot Kennedy a little more than eight days later at the Ambassador Hotel, which served as Kennedy's base of operations on the West Coast.

Hubert H. Humphrey had entered the race at the end of April, too late to enter any primary.  He nevertheless worked with the 36 states that did not hold primaries and the states that everyone that McCarthy won.  He appealed to the moderate faction of the party, the pro-war faction and Big Labor.  The Democratic National Convention was in Chicago, and Richard Daley was a huge Humphrey supporter, as was LBJ.  The Democratic National Convention was marred by riots between anti-war protestors, the Chicago Police and the Illinois National Guard.  He was able to cobble together enough delegates to win the 1968 Primary.  The Chicago Riot, however, basically put him in a hole too big for him to dig out of.  Nixon won California and Oregon en route to winning the Presidency.