ALBANY - Following a strong showing by Democrats in Tuesday's special elections, three Republicans announced this week they're not seeking re-election to the state Senate and more could be leaving too.

The latest to retire is Hudson Valley Sen. John Bonacic, whose announcement on Friday came after Syracuse area Sen. John DeFrancisco confirmed the day before that this would be his last year in the chamber and Sen. Kathy Marchione surprised the Capital Region with her retirement announcement Wednesday. A handful of other Senate Republicans, including one in the Hudson Valley and at least one on Long Island, are rumored to be considering retirement.

Bonacic said that 20 years in the Senate was "enough" and looks forward to spending time with his family.

Senate Democrats, who have been in high spirits following Tuesday's special elections, including a decisive Senate win in Westchester County, maintain that the string of retirements is a recognition of the potential challenges facing Republicans in November. Democrats are expecting the enthusiasm and turnout for their candidates in special elections across the country to continue in New York this fall.

"Clearly the Republicans see the writing on the wall," Senate Democratic spokesman Mike Murphy said in a statement.

Senate Majority Leader John Flanagan greeted the retirements with "mixed emotions" and expressed confidence that Republicans would field excellent candidates to hold on to the seats.

Of the three retirements, Bonacic's seat is the most susceptible to changing hands, based on the voter enrollment. There are about 11,000 more Democrats than Republicans, but there are nearly 43,000 unaffiliated voters and Bonacic won re-election in 2016 by nearly 25,000 votes.

Ulster County Democrat Jen Metzger previously announced her candidacy for the seat and Assemblyman Karl Brabenec, R-Orange County, said on Friday he is "seriously considering running." Orange County Democrat Pramilla Malick is also vying to succeed Bonacic.

Republicans could also be playing defense on Long Island, where Sen. Tom Croci has not committed to running again. One indicator that the Suffolk County Republican won't seek re-election is his nearly depleted campaign war chest, which reported only $2,028 in January, compared to nearly $130,000 at that point in the election cycle two years earlier.

Democratic voters outnumber Republicans by about 8,000 in Croci's district, but about 26 percent of the voters in the district aren't registered with a party.

Suffolk County Republican Committee Chair John Jay LaValle conceded that the race would be tough for Republicans without an incumbent running. "We'll have our hands full, but I believe we can hold it," he said.

Political observers are also keeping an eye out for retirement announcements from Long Island Republican Senators Ken LaValle, Carl Marcellino and Kemp Hannon.

Democrats are hoping that 90-year-old William Larkin, a Hudson Valley Republican, decides not to run again. While the senator cruised to re-election in 2016, Republicans are outnumbered in the district by about 14,000 Democrats.

Larkin's office said the senator has no plans at this time to retire.

Democrats hold a 32-31 edge in the Senate, but Republicans maintain a one-seat majority with the support of Brooklyn Democrat Simcha Felder, who said he will reconsider his allegiances after the legislative session.

Gov. Andrew Cuomo and Senate Democrats are hoping for a "functioning" majority in the chamber next year, which means they'll have to pick up a handful of seats in November.

David.Lombardo@TimesUnion.com - 518.454.5427 - @Poozer87