There was never any chance that the Senate was going to convict Donald Trump. In the House, the Democrats could not persuade a single Republican and lost a few of their own members on the impeachment vote. What chance was there to persuade 20 Republican Senators, even assuming the Democrats could get all of their own 47 Senators to convict (which may not happen)? The entire process from start to finish was theater- designed by the Democrats to weaken Trump before the November election, and force some Republican Senators in competitive races, to cast difficult votes (Collins, Gardner, Tillis, McSally, Ernst, among others). The case itself was the weakest presidential impeachment case ever considered in Congress.
The Democrats, buoyed by the 2018 midterm results, and two governors elections and the Virginia legislative elections in 2019, were confident that 2020 was going to be their year- win the White House, take control of the Senate, hold the House, and win control of a bunch of state legislatures so as to manage redistricting after the census results were announced. It is still over 9 months before the November elections, and anyone who thinks that the results are already baked in, is kidding himself or herself. Even Nate Silver says it is hazardous to predict the Iowa caucus results, which have been heavily polled, and are only 4 days away. One state legislative race in Texas was seen as a possible harbinger of how Texas was changing, a state critical to the fortunes of the GOP, and whether Democratic electoral momentum in the suburbs was continuing. Democrats spent a bunch of money on the race, and had a lot of big name surrogates campaign, and the results were to put it mildly, disappointing . In an open seat race, the GOP candidate won by a much bigger margin than Ted Cruz, who carried the district in 2018, or Trump, who won it in 2016.
https://pjmedia.com/election/bellwether-to-blowout-texas-house-district-gets-redder-to-lead-off-2020-elections/
Nate Silver on Iowa: https://fivethirtyeight.com/features/the-iowa-caucuses-are-in-4-days-almost-anything-could-still-happen/