Donald Trump's still running, but the campaign's over
What a political campaign should be doing right now — even a struggling political campaign — is driving a unified message, contacting voters with that message before they vote and encouraging supporters in early-voting states to get to the polls. It's the Jim Murphys of the campaign who are responsible for doing that.
Trump is now without a Jim Murphy. Even if he could crawl back nationally — probably a decent-sized if — he's now completely reliant on his party to do the hard work of ensuring voters go to the polls. If he doesn't crawl back nationally, or if he doesn't crawl back enough, the party doesn't have a lot of incentive to spend time and money that could instead go to embattled House and Senate candidates.