Trump sunk Republicans in the House. But he likely helped them in the Senate.

Democrats can rightfully claim that a blue wave propelled them to a House majority. Republicans, on the other hand, can say that said blue wave hit a red wall in the Senate, where the GOP gained seats.

What the two sides probably can agree on is this: The results were all about President Donald Trump. Indeed, this midterm was more about feelings toward a president than any other in recent history.

Trump scored a rather low 45% approval rating in the exit polls, compared with a 54% disapproval rating. That 9-point split was reflected in what looks to ultimately be a 7- to 8-point Democratic advantage in the national popular House vote.

A deep dive into the exit polls makes the same general finding: Those who approve of Trump voted Republican, while those who disapproved of him voted Democratic. Approvers went for Republican House candidates by 88% to 11%. A look back at exit polls since 1982 (when presidential approval was first asked on an exit poll during a midterm) reveals that this 77-point margin was the largest ever for the president's party among those who approved of the job the president was doing.

Disapprovers went in the complete opposite direction. They voted for Democratic House candidates 90% to 8%. That 82-point margin among disapprovers was the largest for the opposition party in midterms since 1982 as well.

In the House, this proved to be a disaster for Republicans. The President was, to paraphrase him, on the ballot in every congressional race in the nation. Given that all voters were able to render a decision in the House, this meant an unpopular president resulted in a Democratic-controlled House.

The President perhaps realized this when he chose his final campaign stops. He mostly ignored House races and focused on key Senate matchups throughout the country. Consistently the President visited states that he won in 2016. This strategy, combined with his polarizing rhetoric over issues like Justice Brett Kavanaugh's confirmation battle and the migrant caravan, proved to be smart in Trump's efforts to retain the Senate. It probably contributed to Republican voters coming home and voting for Republican candidates.

Consider the key Senate races of Arizona, Florida, Indiana, Missouri, Montana, North Dakota, Tennessee and West Virginia. His approval rating was at or above his disapproval rating in all these states. With the exception of West Virginia, the Republican Senate candidates won Trump approvers by at least a 76-point margin in all these races. West Virginia and Montana were the only states where the Democratic Senate candidates ended up with more votes than the Republican candidates.

Perhaps more amazingly, the final polls underestimated the Republican candidates' strength in every one of these states except North Dakota. It could be argued that Trump's last-minute whirlwind tour (along with maybe the Kavanaugh hearings) helped line up normally Republican voters behind the Republican Senate candidates in a way not captured by the polls.

These shifts from the final polls turned small Democratic leads in Indiana and Missouri into easy Republican wins. The Senate races in Arizona and Florida, which had slight Democratic leads in the polls, are neck and neck.

Close races in early September in North Dakota and Tennessee became Republican blowouts by October, after the Kavanaugh hearings. That is, the hearings probably brought Trump voters home.

Perhaps most interesting are the polling misfires that turned Montana and West Virginia into far closer races than expected. The Democrats still won, but they had to sweat it out.

Nevada and Texas were the only Senate battlegrounds where Trump's approval rating was not greater than his disapproval rating. Republican Sen. Dean Heller lost in Nevada. Republican Sen. Ted Cruz was one of the few major Republican candidates who actually underperformed his polls.

Unfortunately for House Republicans, they couldn't count on a polling error to bring them victory. Trump was unpopular in the majority of congressional districts, which meant the President polarizing the electorate would not help their cause.

That showed on Tuesday, when Democrats won the House and Republicans won the Senate.