overall vote share. In the 2019 Conservative Party leadership election to determine the final two candidates for the party vote, it was suggested that front-runner Boris Johnson's campaign encouraged some of its MPs to back Jeremy Hunt instead of Johnson, so that Hunt—seen as "a lower-energy challenger"—would finish in second place, allowing an easier defeat in the party vote. Strategic voting was expected to play a major role in the 2019 General Election, with a YouGov poll suggesting that 19% of voters would be doing so tactically. 49% of strategic voters said they would do so in the hope of stopping a party whose views they opposed. According to a 2020 study, older voters in the UK vote strategically more than younger voters, and richer voters vote more strategically than poorer voters. United States Strategic voting in the US's first-past-the-post voting and presidential system contributes to a two-party system, where the observed effect of Duverger's law is stronger than in most countries. One high-profile example of strategic voting was the 2002 California gubernatorial election. During the Republican primaries, Republicans Richard Riordan (former mayor of Los Angeles) and Bill Simon (a self-financed businessman) vied for a chance to compete against the unpopular incumbent Democratic Governor of California, Gray Davis. Polls predicted that Riordan would defeat Davis, while Simon would not. At that time, the Republican primaries were open primaries in which anyone could vote regardless of their party affiliation. Davis supporters were rumored to have voted for Simon because Riordan was perceived as a greater threat to Davis; this, combined with a negative advertising campaign by Davis describing Riordan as a "big-city liberal", allowed Simon to win the primary despite a last-minute business scandal. The strategy to nominate Simon (if in fact it was a reality), was successful, as he lost in the general election against Davis. Puerto Rico Puerto Rico's 2004 elections were affected by strategic voting. Pedro Rosselló, the New Progressive Party's candidate of that year, was unpopular across much of the territory due to large corruption schemes and the privatization of public corporations. To prevent Rossell from winning, other factions supported the Partido Popular Democratico's candidate. The elections were close; statehood advocates won a seat in the U.S. house of representatives and majorities in both legislative branches, but lost governance to Aníbal Acevedo Vilá. (Puerto Ricans have the chance to vote by party or by candidate. Separatists voted