I've culled through several articles in which the recent US elections have been analyzed, and pulled the following snippets from three of them.
In short, the Republicans did fairly well overall, and much better than Obama did at the same point, and President Trump stands an excellent chance of re-election two years hence.
https://news.gallup.com/opinion/polling-matters/244661/providing-context-midterm-election-results.aspx?g_source=link_NEWSV9&g_medium=SIDEBOTTOM&g_campaign=item_242093&g_content=Providing%2520Context%2520for%2520the%2520Midterm%2520Election%2520Results
Perhaps most critically, the 34% who specifically said they were voting to oppose Trump was consistent with anti-presidential fervor in 2014 and 2010, when Obama's party lost seats.
More than six in 10 Democratic and Democratic-leaning voters (62%) said they were sending a message of opposition to Trump, similar to the proportion of Republican and Republican-leaning voters who were doing the same against Obama in 2014 and 2010 (58% each).
https://www.washingtonpost.com/opinions/if-the-midterms-were-a-referendum-trump-won/2018/11/09/a39cc5fe-e44f-11e8-ab2c-b31dcd53ca6b_story.html?noredirect=on&utm_term=.13421cc18d12
After flipping dozens of seats in the midterm elections, Democrats are set to take control of the House of Representatives. Many pundits and analysts have attempted to frame the results as a referendum on President Trump. Among these, there seems to be a consensus that the president has somehow been "repudiated."
It was expected that the Republicans would lose a significant number of seats, irrespective of public opinions about Trump. Republicans had many more difficult House seats to defend than Democrats overall. There were twice as many Republican incumbents defending House seats in states Hillary Clinton won in 2016 than there were Democrats defending seats in states Trump won.
Republicans also had more than twice as many "open" House seats to hold on to as their Democratic rivals had: 36 Republican representatives chose not to stand for reelection this year because they were retiring or seeking another office. Seven others either resigned or otherwise left office before the election. As a result, Republicans had 43 House seats to defend without the benefit of a true incumbent candidate. On top of this, Republicans had three "open" Senate seats, and one more with a pseudo-incumbent (interim Mississippi Sen. Cindy Hyde-Smith took office in April).
Yet Democrats managed to win surprisingly few of these "open" contests. In the vast majority of cases, a new Republican was elected instead, and they tended to be even closer to Trump than their predecessors. So Trump actually cemented his hold over the Republican Party: Most of his staunchest Republican critics have either stepped down, been removed through a primary challenge or otherwise failed to win reelection. On top of this, many of the Senate Democrats who voted against Supreme Court Justice Brett M. Kavanaugh from the states that Trump won in 2016 were voted out of office and replaced by Republicans.
Historically speaking, Democrats delivered a thoroughly average result in their first round as Trump's opposition. Going all the way back to the Civil War, there were only two instances when a new party seized the presidency but didn’t lose seats in the House during their first midterm elections: Under President Franklin D. Roosevelt in 1934 (during the Great Depression), and President George W. Bush in 2002 (in the shadow of the 9/11 terrorist attacks). Even including these outliers, the average attrition during a party's inaugural midterms is 35 House seats; excluding these two exceptions, the average loss is 41. Regardless of which number we run with, Trump could end up performing better than average in preserving his party’s influence in the House. He performed much better than his last two Democratic predecessors: Bill Clinton lost control of both chambers in the 1994 midterm elections. Barack Obama saw historic losses in the House in 2010, and lost seats in the Senate as well - the most sweeping congressional reversal in 62 years. (Sixty-three House seats, and nine Senate seats, although a couple of sources had a different number of Senate seats lost - Loachman)
Yet, not only did Trump suffer far less attrition than Obama or Clinton in the House, his party will gain in the Senate. This may not be surprising given the slanted map against Democrats. It is also somewhat typical overall: Between 1862 and 2014, the president's party picked up seats in the Senate during their first midterms 56 percent of the time, lost seats 37 percent of the time and broke even once. In other words, there did not seem to be a thorough rebuke of Trump. In fact, there was little exceptional in the results at all, beyond the fact that they were so very normal.
This reality should make Democrats deeply anxious because, as I've demonstrated elsewhere, if the 2020 presidential election similarly conforms to historical tendencies, the odds are roughly 8 to 1 that Trump wins reelection.
Indeed, the president's inaugural midterm results are eerily similar to those of another entertainment-star turned political game-changer: Ronald Reagan. In 1982, his party lost 26 seats in the House - but picked up one seat in the Senate. He, too, faced a split Congress. His approval rating going into those midterms was also in the low 40s. He went on to win reelection by a landslide in 1984.
https://www.investors.com/politics/editorials/trump-approval-rating/
Despite the overwhelmingly negative coverage of his administration, President Donald Trump's approval rating is as high or higher than half of the previous six presidents at this point in their first terms.
(But) according to the Gallup Poll, Trump's approval rating as of his 632nd day in office was 44%.
Is that good or bad? That depends on the context. Trump has never polled well. Gallup had his approval rating at 45% the day he took office.
The mainstream press focused intensely on Trump's initial rating, which was well below those of any president since Gallup first started tracking this in 1945.
Even Gerald Ford's approval rating 90 weeks into his accidental presidency was 71%.
But the press lost interest in such comparisons as time went by.
Perhaps one reason is that, by this point in their first terms, approval ratings for most presidents had declined. Sometimes sharply.
As a matter of fact, Trump's approval rating is now higher than, or tied with, three of the past six presidents at this point in their first terms.
He's currently tied with Obama (at 44%), and above both Clinton (41%) and Reagan (42%).
Obama's approval rating on day one was 67%, but steadily declined as his economic policies failed to re-energize the economy, despite the massive stimulus, while he forced through the highly unpopular Obamacare.
Clinton's eroded after he broke his promise on tax hikes.
At this point in Reagan's first term, the economy was in a painful recession, and unemployment was above 10%.
Needless to say, each went on to win re-election handily.
But look at who scored higher than Trump: George W. Bush (67%), George H.W. Bush (56%), and Jimmy Carter (49%). W. was coming off his sky-high approval rating in the wake of 9/11, which peaked at 90%. He ended his second term at 34% approval. George H.W. had just started building up troops in preparation for liberating Kuwait in Operation Desert Storm. Carter had recently signed the Camp David Accords.
What does all this mean?
First, it means that anyone who thinks Trump's low approval ratings today are a problem for his re-election prospects is mistaken. There's no correlation. Three presidents with ratings as low or lower than Trump's served two terms. Two with much higher approval ratings at this point ended up as one-term losers.