2016 Republican primaries. Trump won more support in 39 of the 54 contested nomination fights in 2016, according to a review of the year’s results. That includes nine wins after he locked up the nomination with a victory in the Indiana primary.
2016 general election. Trump won more electoral votes than Hillary Clinton but lost the popular vote by 2.9 million ballots. Republicans also saw their House majority slip by six votes and lost two Senate seats.
2018 elections. Trump made more than 130 endorsements in 2018, including both primary and general election endorsements for some candidates. Most of his endorsed primary candidates won (35 of 37) but his candidates won a bit over half of their general-election fights (56 of 95). That includes six state-level candidates in Texas, for example, as well as several almost-certain red-state governor candidates.
Nationally, his party was battered, losing more than 40 seats in the House. Republicans gained two seats in the Senate, thanks to a favorable map (picking up seats Democrats gained in the 2012 presidential cycle), something that Trump seized upon as proof of his effectiveness as a party leader.
2020 elections. The Republican Party was assertive about boxing out challengers to Trump in the 2020 party primaries, rendering an assessment of those contests about as useful as parsing the vote totals for Kim Jong Un’s most recent reelection bid.
He made more than 300 endorsements in primary and general-election contests, with his primary candidates winning in 117 of the 121 identified by Ballotpedia. In general elections, his candidates won 142 of 182. Those wins were again driven higher by endorsing numerous incumbents; more than half of his wins were incumbents winning primaries and then retaining their positions.
The marquee race that year, of course, was his own, with Trump again losing the popular vote as he also trailed in the electoral college. His party also lost control of the Senate, though it did add 14 seats in the House.
2022 elections. With an eye on announcing his candidacy for the 2024 presidential nomination, Trump made nearly 500 endorsements in the most recent cycle. Most were successful, thanks to his making a number of endorsements aimed at boosting his total. (His endorsement of Doug Mastriano’s gubernatorial primary bid in Pennsylvania, for example, came only after it was clear Mastriano would win — and as it seemed possible that his endorsed Senate candidate, Mehmet Oz, might not make the general.) In total, Trump’s candidates won 224 of 241 primary races and 208 of 254 general-election ones.
Ballotpedia also broke out key battleground races for 2022, contests that weren’t simply Trump rubber-stamping the likely Republican winner. In those, they estimate, Trump’s candidate won in only 14 of 37 general-election contests (though the results are incomplete, awaiting other election calls). That includes Oz’s loss in Pennsylvania.
Overall, Trump’s party underperformed expectations, failing to retake the Senate while only barely taking a majority in the House. For Democrats, it was a surprisingly good year, given how midterm elections usually go for the party of a new president.