Pennsylvania Lt. Gov. John Fetterman ended June with more than $3 million in his U.S. Senate campaign account, a sign of his growing financial muscle as a competitive Democratic primary unfolds.

Fetterman’s fund-raising prowess reflects how much has changed since 2016, when he ran an underdog Senate campaign that generated buzz but couldn’t match the financial power of his Democratic rivals. Now as a statewide elected official, Fetterman is seen as the early Democratic front-runner, and is likely to far outpace the field in financial resources.

His cash-on-hand figure is almost five times the amount reported by one of his top competitors, Montgomery County Commissioner Val Arkoosh, though he’s been in the race several months longer. State Rep. Malcolm Kenyatta of Philadelphia has lagged behind both, raising about $374,000 in his first few months as a candidate. He hasn’t yet announced his second quarter figures, which are due Thursday.

Arkoosh raised about $1 million and had $632,000 on hand after her first three months in the campaign. But she also has the backing of EMILY’s List, a Democratic women’s group that often spends heavily to aid its chosen candidates — including in Pennsylvania’s 2016 Democratic primary, when it helped power Katie McGinty to the nomination.

» READ MORE: Pennsylvania Gov. Tom Wolf says he won’t endorse anyone for Senate — including his lieutenant, John Fetterman

Fetterman had previously announced collecting $2.5 million in the fund-raising period covering April, May, and June, but had not disclosed how much money was left in his campaign account. He spent about $1.4 million in those three months.

“We are reinvesting our donations back into the campaign which is allowing us to build a long term and unparalleled operation,” a Fetterman spokesman said.

Fetterman has 52,000 Pennsylvania donors, according to his campaign, which it calls a sign of his grassroots strength in a Senate race that could break spending records.

Both parties see Pennsylvania’s Senate race as one of the most critical in the country, one of a handful likely to decide control of the chamber and the fate of President Joe Biden’s agenda after 2022. Incumbent Republican Sen. Pat Toomey isn’t seeking reelection.

The latest quarterly fund-raising reports for federal candidates are due Thursday, with party insiders looking to them as early measures of strength as campaigns take shape.

Other top Democrats considering Senate runs include U.S. Rep. Conor Lamb of Allegheny County and State Sen. Sharif Street of Philadelphia.