The contests were a microcosm of several national political themes the parties are confronting, including the embrace of Republican candidates fashioned in the style of Mr. Trump, the left-wing push to unseat more centrist House Democrats, and another trial run for the mail-in voting system that has become a lifeline for states struggling to deal with the pandemic.
On the Republican side, the Kansas Senate race in particular offered another reminder that the party divisions that existed before Mr. Trump won will persist even after he leaves office. That includes the disagreement between deeply conservative activists, who are skeptical of Washington and approve of the type of white identity politics Mr. Trump has embraced, and the party’s traditional establishment — many members of which have argued that such messaging hurts the party long-term.
The failure in Missouri of Ms. Bush, who also ran unsuccessfully in 2018, shows the limits of the current left-wing efforts to remake the House Democratic caucus. Since 2018, progressives have found some success in districts with a white incumbent and a majority-minority population, a pathway executed by successful House challengers like Alexandria Ocasio-Cortez in New York, Ayanna Pressley in Massachusetts and Jamaal Bowman in New York, who coupled the insurgent message of ideological change with an argument about racial representation.
This has not worked for challengers trying to defeat Black or Latino members of the party’s establishment, such as Mr. Clay. Earlier this year, other longtime Black caucus members in Ohio and New York also easily defeated challengers, dashing hopes among the progressive left that longtime lawmakers could be ousted.
States handled the election activity Tuesday with moderate success, as Americans continued to show a degree of comfort with mail-in and absentee voting systems even as Mr. Trump and his allies have sought to sow distrust. In Michigan, where Representative Rashida Tlaib’s bid to win a second term in Congress was the most closely watched but where there was also an open House seat, more than 1.5 million voters had turned in an absentee ballot by late Tuesday afternoon, according to election officials, a sizable portion of the total electorate.
The contests unfolded at a moment of extraordinary turmoil in the nation, capping a summer defined by a pandemic and economic crisis, as well as a national outcry over racism and police brutality. And on both sides of the aisle, the races tested enthusiasm for voting amid a public health crisis.