The shift was apparent Wednesday, the morning after the Pennsylvania primary, when the Clinton campaign appeared to preview their anti-Trump strategy by blasting out a series of messages and tweets critiquing Trump ahead of his foreign policy speech.
"Nothing he can say can hide the long list of dangerous national security proposals he’s put forward over the course of this campaign,” the campaign wrote in a lengthy memo titled, “Loose Cannons Tend to Misfire,” highlighting some of Trump's "most irresponsible comments and proposals."
Meanwhile, Clinton herself tweaked her speech on Tuesday night to suggest she has her eye on November.
She vowed to unify the Democratic Party -- a message seemingly aimed at Sanders, who has been hesitant to say he would endorse Clinton if she becomes the nominee.
"Whether you support Senator Sanders or you support me, there's much more that unites us than divides us,” Clinton exclaimed. "I applaud Senator Sanders and his millions of supporters for challenging us to get unaccountable money out of our politics and giving greater emphasis to closing the gap of inequality and I know together we will get that done.”
Clinton also appeared to begin a push to woo Republicans (specifically those more moderate ones who are not supporters of Trump or Ted Cruz). She called on anyone who is a “thoughtful Republican” to consider her message and campaign.
"So my friends, if you are a Democrat, an independent or a thoughtful Republican, you know their approach is not going to build an America where we increase opportunity or decrease inequality,” she said. "So, instead of letting them take us backwards, we want America to be in the future business. That's why I want you to keep imagining a tomorrow where instead of building walls, we're breaking down barriers.”
Trump has also shifted his focus to Clinton in recent days, taking her on more directly during his campaign events and saying he plans to study Sanders' playbook. ("I can re-read some of his speeches and get some very good material," Trump said on MSNBC about his plans to go after Clinton.)
Sanders has yet to tone down his critiques of his opponent, and has vowed to stay in the race through the convention, however, the reality of the race is settling in. His campaign is set to lay off hundreds of staff members.
"As a result of the process moving forward with only ten states to go, we need fewer people in place to do the work [than] we needed when there were 50 states to go," Sanders campaign spokesman Michael Briggs said in a statement. "And so the campaign is doing some right-sizing to deal with the practicability that we have fewer states left to go."