He has certain skills, but President Trump also benefits from lucky timing. And his impeachment trial fell at an ideal time on the economic calendar.

The Senate will almost certainly acquit Trump this week—ending the impeachment drama—as the unemployment rate is at a 50-year low and the stock market is close to record highs. The economy itself is (probably) in the late stages of the longest business-cycle expansion on record. Consumers feel upbeat and don’t have to worry about what is normally their No. 1 concern: jobs and the economy.

Trump’s party-line acquittal will occur because his approval rating, which is in the low 40s among all voters, is nearly 90% in the Republican party. Roughly the same portion of Republicans say they approve of Trump’s handling of the economy, according to Morning Consult. Only 21% of Democrats and 47% of Independents feel the same way. So views on the economy essentially unify Republicans in their support of Trump.

It’s possible some Republican senators will vote to acquit Trump because they genuinely believe his transgressions regarding Ukraine were not impeachable. Okay, done laughing? Now for reality: Senate Republicans can’t buck Trump because he’s notoriously vindictive and would try to end their political careers. And his near-unanimous support in the Republican party might allow him to do it.

Trump’s approval in the party would be lower—perhaps far lower—if the economy were weaker or a recession hit. Analysis of Trump voters in surveys such as the Democracy Fund’s Voter Study Group shows that some Trump supporters would truly back him no matter what, for cultural reasons not pertaining to the economy. But maybe two-fifths of Trump’s support comes from voters who feel things are fine, so why risk messing anything up? Some of those voters don’t even like Trump, but they feel his tax cuts and deregulatory efforts have been an economic boon.

The economy under Nixon, Clinton

Richard Nixon didn’t have the fortune of a solid economy behind him when he resigned in August 1974. The economy back then had actually entered a recession, with GDP falling from a 7.6% annual growth rate at the start of 1973 to -0.6% in the third quarter of 1974. The unemployment rate during the same period rose from 4.9% to 5.5%, and was on its way to getting much worse. Inflation had crested 10%. Consumers were jittery, for good reason.

Nixon’s approval rating plummeted as the economy weakened. By the time he left office, it had plunged from a high of 67% to a dismal 24%, the lowest of his presidency. The unfolding Watergate scandal undoubtedly helped knock Nixon down, but, as with Trump, voters had mixed views on the matter. Polls by Gallup, Harris and others showed that nearly half of voters felt the Watergate scandal was overblown. Nixon’s overall approval rating was far lower than the portion of voters who felt he should resign, largely because the economy was turning lousy.