WASHINGTON — Next, more of the same, but with more entrenched division, a bitter crossfire of allegations and then, finally, a reckoning in the form of the 2020 presidential election. The long-awaited conclusion of special counsel Robert S. Mueller III’s investigation into Russian interference in the 2016 election is likely to harden congressional Republicans’ wall of support for President Trump, strengthen Democratic demands to hold Trump to account — and result in little change in public opinion, according to historians and politicians who have studied past national scandals. Mueller’s conclusion — he found no evidence of collusion with Russia but […]