Rep. Marty Walsh, left, and City Councilor John Connolly shake hands with residents earlier in the mayoral race. (Jesse Costa/WBUR)

City Councilor John Connolly and state Rep. Marty Walsh, the two finalists in Boston's most competitive mayoral race in a generation, have sometimes struggled to distinguish themselves on the stump.

But for close watchers, the campaign between these two white, progressive Democrats has illuminated some significant — or, at least, noteworthy — differences.

With voters set to cast ballots Tuesday, here are four places where the candidates part ways.

Background

Walsh grew up in a triple-decker in a blue-collar section of Dorchester, the son of Irish immigrants. His father was a laborer. And Walsh worked briefly in construction before climbing the ranks of union leadership.

Walsh struggled with alcoholism as a young man before winning a seat in the state Legislature, where he's pushed for social services and served as a liaison between organized labor and legislative leadership. He stepped down from his post atop the Boston Building Trades, an umbrella union group, to run for mayor.

Connolly grew up in Roslindale, the scion of a prominent political family. His father was a four-term secretary of state, his mother a lawyer who would later become a judge.

Connolly graduated from Harvard University and taught for three years in urban schools in New York and Boston — an experience he's called the most impactful of his life. Later, he worked as a corporate lawyer. In 2007, he won a seat on the City Council, where he has made education his signature issue.

Walsh and outside labor groups supporting him have played up the biographical differences. Fliers from outside groups call Connolly a "son of privilege." Connolly has pushed back — Roslindale, he cracks, is no Beverly Hills. And with union forces working overtime to elect Walsh, Connolly has pitched himself as the underdog in recent days — the independent figure taking on the machine.

The campaign, like so many others, has devolved into caricature at times. Walsh is more than a union guy; Connolly more than a lawyer. But it seems clear that the candidates' backgrounds have informed their perspectives.

Walsh supporters talk, among other things, about his innate understanding of people's struggles and his personal support for recovering alcoholics and addicts.

Connolly's backers are drawn, in part, by his push to apply the latest ideas in urban policy to the problems of poverty.

Education

A WBUR poll showed education is the voters' top concern. And while there is plenty of overlap between the candidates on education policy, there are important differences.

Connolly is the most prominent local voice for a national education reform movement that favors a market-based approach: charter schools, teacher accountability and a devolution of power from the superintendent to individual principals.

The idea is that Boston's school system is too beholden to an outdated, dysfunctional bureaucracy. The system, in this view, should be a mosaic of empowered local schools tuned to the specific needs of their populations.

Connolly says a major shake-up of the school system, combined with help from a rich network of nonprofit and university partners, could make Boston the first major city in the country to close the "achievement gap" separating white students from blacks and Latinos.

Walsh has warned that Connolly's plan to "blow up" the school system is too risky — and that students could suffer from the upheaval. The labor leader says he'd work with the teachers union to improve the schools — calling Connolly's "line in the sand" approach too confrontational to be productive.

Walsh is focused on providing universal preschool for 4-year-olds. He also wants to improve the high schools — forming "academies" for ninth- and 10th-graders too often shuttled through the system and adding more trade programs tailored to the modern economy.

But if Walsh's signature proposals are more traditional in bent, he lays some claim to the education reform movement. Walsh serves on the board of a charter school in Dorchester and says the state-imposed cap on charter schools should be lifted.

Development

It is hard to overstate the role of the Boston Redevelopment Authority in shaping the city's landscape.

Formed in 1957 in the age of urban renewal, it has razed the West End, built City Hall and helped shape the South Boston waterfront. It's also been a key lever of power for a series of Boston mayors.

Critics have called the agency too powerful and too opaque; it favors certain developers, they argue, and does not give neighborhoods enough of a voice.

Walsh has called for the most sweeping change: a dismantling of the BRA and the creation of a new economic development agency more independent of the mayor and subject to City Council oversight.

Connolly does not want to pull the BRA apart. But he is calling for more transparency at the agency. And he says there should be more separation between its planning and development functions.

Those functions are separate in most cities — there is a natural tension between planning for a city's long-term growth and the urgency of getting projects in the ground.

Both candidates say members of the BRA board should be term-limited.

Casino

Voters in East Boston (and Revere) will either approve or shoot down a proposed casino at Suffolk Downs on Tuesday.

For much of the campaign, the two mayoral candidates studiously avoided taking a position on the question -- loathe to alienate voters on either side of the issue, it seemed.

That changed in the final televised debate between the two candidates. When asked how they'd vote as Eastie residents, Walsh came out in favor of the casino — citing the jobs it would create.

Connolly declined to take a position, but emphasized that the last-minute withdrawal of gambling giant Caesars Entertainment from the project is "troubling."