Mikulski, a Democrat and former chair of the House Appropriations Committee, sent Maryland's Republican governor a letter saying she needs his assistance to secure funding for the east-west Purple Line light rail project designed to connect Maryland's Washington suburbs.
"We must work together across party lines to meet the nation and Maryland's compelling infrastructure needs," Mikulski wrote. "These include economic development investments like the Purple Line, mass transit, and highways."
The proposed 16-mile Purple Line stirred controversy in Maryland over its price tag and concerns about whether Hogan would find it too costly to move forward. Ultimately, Hogan decided to pursue the $2.4 billion Purple Line and scrap the $2.9 billion Red Line planned for Baltimore.
Mikulski said she made sure that the Purple Line received $100 million in federal dollars last year. But as Congress faces gridlock over a budget deal, her letter suggests that future funding might be in jeopardy.
"Congress is again at a stalemate on how to proceed with the annual appropriations bills, and federal funding is severely limited because of sequestration," Mikulski wrote. "That is why I need your assistance in reaching out to House and Senate leadership to work on a budget deal that lifts the spending caps."
Hogan did not appear eager to help.
His spokesman, Matthew A. Clark, said Maryland's congressional delegation had assured the governor in January that the Purple Line would get up to $900 million in federal cash.
"Marylanders are weary of the dysfunction in Washington and are eager to see their representatives put aside partisanship and get things done," Clark said.
Clark said Hogan has promised to put $168 million in state money into the project — down from its original share of $700 million — and that leaders in Prince George's and Montgomery counties have also put up money.
"All that remains is for Maryland's representatives in Washington to ensure that the $900 million federal funding is appropriated," Clark said.
Baltimore Sun reporter John Fritze contributed to this article.