The political conventions are over, but the intense race for cash is just ramping up.

Candidates in contested primaries have just 10 weeks to close the deal with voters, after which they face the most expensive hurdle of all — the sprint to November.

"We are probably going to need to raise a million bucks to win the primary and maybe, another two and a half to three to win the general [election]," said Jeff Johnson, the newly endorsed Republican candidate for governor. For Johnson, a Hennepin County commissioner, the quest for cash is particularly pressing.

Johnson will face three Republicans in the Aug. 12 primary: former legislator Marty Seifert, former House Speaker Kurt Zellers and businessman Scott Honour, and none of them likely spent what Johnson did in wooing delegates. Seifert tried for the endorsement but quickly fell behind. Zellers and Honour skipped the endorsement process.

According to a Star Tribune analysis of campaign finance reports, Johnson has raised about $280,000 since getting into the race almost a year ago. But he has spent an average of $411 per day, with spending doubling this year while his per-day fundraising dropped. Johnson has spent about $56,000 on staffing, overhead and consultants, with another $40,000 going to postage and advertising. Johnson actually spent more on campaign expenses than he raised in the first three months of the year.

"I don't know how much I have left in the bank right now," Johnson said Monday. He said that after the convention, fundraising and the response have become more intense.

Seifert, a 2010 candidate for governor, has raised $214,000 so far and spent an average of $471 per day since getting into the race in late October, with the bulk of his spending coming early this year. He has, on average, raised about $900 more per day than he has spent. His single largest expense — $24,000 — so far has been on overhead.

Zellers has raised more — nearly $500,000 — but spent it just as quickly. Comparing average cash raised per day to average daily spending, he would have just $251 left per day. But his biggest expense may be something that could pay dividends through the August primary. Zellers' campaign spent nearly $250,000 — half of what he's brought in — on lists and databases.

Honour has raised more than any of the other GOP contenders but spent far more as well. According to the latest reports, he brought in nearly $900,000, which included a $150,000 loan to himself. Staff and consultants, including manager Pat Shortridge and fundraiser Shanna Woodbury, have been his biggest cash draws by far. Shortridge's consulting firm had been paid $142,000 and Woodbury's firm brought in $127,000 from Honour's campaign, according to reports due in mid-April.

"We will continue to make sure that we have the resources to win," said the former California-based private equity director. In late May, Shortridge said Honour had added another $250,000 from his pocket to the campaign.

In 2010, DFL Gov. Mark Dayton, an heir to the Dayton department store fortune, put nearly $4 million of his own wealth into his primary and general election campaigns. Asked if he would be willing to spend a similar amount, Honour demurred.

"I'm not putting a number on it," he said. Twitter: @RachelSB 612-673-7192