By Nathan Layne
(Reuters) - President Joe Biden and former President Donald Trump are both expected to easily win primaries in four states on Tuesday, including battleground Wisconsin, after clearing the field of challengers and clinching their parties' nomination.
Both candidates continue to contend with protest votes, however, and political observers will be paying close attention to their margins of victory for potential signs of weakness heading into their general election rematch in November.
In Biden's case, some Democratic voters who oppose his backing of Israel's military offensive in Gaza have marked "uncommitted" on their ballots in a show of protest. For Trump, the focus will be on how many votes he loses to former U.N. Ambassador Nikki Haley, who dropped out of the Republican primary this month and was his last remaining challenger.
In addition to Wisconsin - one of six or seven swing states expected to determine the outcome of the presidential election - voters will go to the polls in the solidly Democratic states of Connecticut, New York and Rhode Island.
Lawmakers in Delaware canceled the state's April 2 primary after Haley dropped out of the race, leaving Trump as the Republican candidate. All of its delegates will be assigned to Trump and Biden, who did not have a challenger in the state.
Here is a look at what is happening on the ground in Tuesday's Democratic and Republican primaries.
CONNECTICUT
Republican delegate count: 28
Democratic delegate count: 60
The polls close at 8 p.m. ET.
Some Connecticut Democrats are expected to vote "uncommitted" as a way to protest Biden's handling of the Israel and Gaza war, though there is no sign of organizing on the scale seen in Michigan, where the state's substantial Arab American population drove the "uncommitted" vote to 13% of the Democratic Party's total.
Democrats wishing to register a protest vote can also select Marianne Williamson, the self-help author who relaunched her campaign in late February; U.S. Representative Dean Phillips, who ended his long-shot challenge to Biden in March but is still on the ballot; or progressive media personality Cenk Uygur, who has also exited the race.
Republicans not supportive of Trump will also have the choice of marking "uncommitted" on their ballots as well as selecting former presidential candidates including Haley, Florida Governor Ron DeSantis, or Texas-based businessman and pastor Ryan Binkley.
Connecticut is a Democratic stronghold. Biden beat Trump by 20 percentage points in the 2020 general election.
NEW YORK
Republican delegate count: 91
Democratic delegate count: 268
The polls close at 9 p.m. ET.
While "uncommitted" is not an option on the ballot in New York, a group of activists has launched a "Leave it Blank" effort encouraging Democrats to submit blank ballots instead of registering a vote for Biden. However, the state's Board of Elections has said it would not include such votes in its unofficial election night results.
Williamson and Phillips join Biden on the Democratic ballot, while several of Trump's former Republican rivals also remain on their party's ballot.
Biden won New York by 23 percentage points in 2020.
RHODE ISLAND
Republican delegate count: 19
Democratic delegate count: 26
The polls close at 8 p.m. ET.
Voters in Rhode Island will have an "uncommitted" option on both ballots, as well as voting for former rivals of both Biden and Trump.
Biden won Rhode Island by nearly 21 percentage points in 2020.
WISCONSIN
Republican delegate count: 41
Democratic delegate count: 82
The polls close at 9 p.m. ET.
Organizers in Wisconsin calling for a protest vote against Biden are urging voters to choose "uninstructed," Wisconsin's version of an uncommitted vote. They have set a modest goal of 20,682 "uninstructed" votes – the margin Biden won the state by in 2020, less than 1% of the vote in that election.
Wisconsin has an open primary system, meaning voters can participate in either the Democratic or Republican primary.
Primary participants will also vote on two referendum questions.
One would amend the state constitution to say that only election officials can conduct election-related tasks - a step Republicans have said is necessary to restrict any outside influence. Opponents of the change say the wording is vague and could limit the vital role played by volunteers.
The other ballot measure would prohibit the use of private funds - dubbed "Zuckerbucks" by critics - to run elections. Republicans are eager to ban outside election funding after a foundation funded by Facebook (NASDAQ:META) CEO Mark Zuckerberg donated hundreds of millions of dollars in various states to help local governments administer the 2020 election. Republicans have claimed the funds were aimed at boosting turnout in Democratic cities.