President Trump and House Republicans are stepping up their calls for an additional round of tax relief this year, but procedural and political roadblocks are likely to thwart the GOP’s election-year tax plans.

The sweeping $1.5 trillion tax cut law Congress enacted last December lowers taxes for both individuals and businesses. But most of the tax benefits for individuals and families – from the new brackets and lower rates to the expanded standard deduction – will expire after 2025 unless Congress votes to renew them.

House conservatives are hoping to leverage those expiring provisions to build momentum for a vote on a new tax bill before the November midterm elections, where the Republicans’ House and Senate majorities are at stake. House Ways and Means Committee Chairman Kevin Brady, R-Texas, has signaled interest in additional tax legislation this year, and Trump has recently promoted the idea in a series of tweets.

Business stakeholders also like the idea of a fresh round of tax cuts. Legislation that makes permanent the individual provisions also could carry other business-friendly provisions, like eliminating the 2.3 percent excise tax on medical device manufacturers.

While Republicans may successfully push a new tax cut bill in the House, it’s likely to stall in the Senate.

That’s because 60 votes are required to approve most bills in the Senate. But Republicans’ Senate majority is wafer-thin: The GOP holds only 51 seats – and Sen. John McCain, R-Ariz., has been absent for months following treatment for brain cancer.

In addition to the procedural challenges, the politics of a new tax cut bill don’t align for Republicans either. That’s because several Senate Democrats are facing competitive re-elections this year, including Sens. Claire McCaskill, D-Mo.; Joe Manchin, D-W.Va.; Joe Donnelly, D-Ind.; Bill Nelson, D-Fla.; John Tester, D-Mont.; Sherrod Brown, D-Ohio; and Heidi Heitkamp, D-N.D. It’s not in Senate Republicans’ interests to give these vulnerable senators a political freebie – an opportunity to vote to cut taxes for individuals and families right before their re-elections.

It’s possible Republicans will push tax legislation in Brady’s committee and even schedule a vote in the House. But the likelihood of a tax bill being signed into law before the November midterm elections is low.